The combined lifestyle intervention CooL in times of COVID-19: a descriptive case series study

doi:10.21203/rs.3.rs-2593810/v1

Background

The main objective of this nationwide study was to investigate changes over time of participants after eight months of participation in the Combined Lifestyle Intervention CooL (Coaching on Lifestyle) regarding health perceptions, self-mastery, dietary intake, physical activity, alcohol use, smoking, sleep, stress management and anthropometry. Since the study took place when the COVID-19 pandemic emerged, we were able to address changes over time while participants were exposed to pandemic-related restrictions and uncertainties.

Methods

Data were collected from November 2018 until October 2021 at different locations across the Netherlands from 1824 participating adults, meeting the Combined Lifestyle Intervention inclusion criteria. We collected a broad set of data on anthropometrics, behaviours and health perceptions.

Results

The results indicate that the COVID-19 pandemic impacted negatively on changes in self-mastery, perceived fitness and stress, but not on anthropometric outcomes, diet, sleep or social support. Overall, the outcomes show improvements in health perceptions, behaviours and weight after eight months compared to baseline. The largest effect sizes were found on weight, waist circumference, perceived health and the awareness around diet (i.e. attentiveness for diet, amount of food and consuming food).

Conclusion

Participating in CooL appeared to protect against engaging in unhealthy behaviour during the pandemic, despite a decreased sense of self-mastery and increased stress. The results support the lifestyle coaching approach that small changes in multiple behaviours can synergistically contribute to better (perceived) health and health-related outcomes.

lifestyle

CooL

overweight

obesity

COVID-19

In 2021, 50% of Dutch people aged 18 and older were overweight and approximately 14% were obese (1). Obesity is considered a disease according to the World Health Organisation (2) and the Dutch Health council (3). Furthermore, obesity is associated with an increased risk for many other diseases, such as diabetes mellitus type 2, cardiovascular disease, various cancers (4),(5),(6), mental health problems (e.g., depression) (7) and a diminished quality of life (8). Consensus has been reached internationally (9) on the importance of an integrated approach to target overweight and obesity, including limited energy intake, healthy food choices and regular physical activity. The Dutch national guidelines added stress management and sleep as essential elements to tackle overweight and obesity (10).

As of January 2019, Combined Lifestyle Interventions (CLIs) are part of basic health insurance in the Netherlands. A CLI is an intervention for people with overweight or obesity, stimulating weight reduction by promoting sustained healthier behaviour. In the intervention, participants are coached towards a healthier lifestyle. The CLIs exist of a combination of group and individual sessions and cover at least the topics of healthy diet, physical activity and behavioural change. Based on the relationship between stress and obesity and sleep and obesity, and the Dutch national guidelines, these lifestyle themes are considered an essential part of the CLI (11), (12).

The inclusion criteria for CLIs in the Netherlands are: (1) being 18 or older; (2a) having a Body Mass Index (BMI) between 25 and 30 kg/m2 in combination with a waist circumference over 88cm for women and over 102cm for men, or with comorbidity ((increased risk of) diabetes or cardiovascular disease, osteoarthritis or sleep apnea), or (2b) having a BMI > 30 kg/m2 regardless of waist size or comorbidity; and (3) being sufficiently motivated to complete the two-year intervention as judged by the referrer (e.g. the general practitioner or practice nurse) and the CLI-coach.

The Coaching on Lifestyle intervention (CooL) is one of the six CLI’s that are approved by the Dutch Institute for Public Health and Environment (in Dutch: RIVM) for being sufficiently effective in facilitating weight reduction. The intervention has two phases: a behavioural change phase in the first 8 months, followed by a 16-month behavioural maintenance phase. So far, research on CooL has been done with participants of two regional pilots: the CooL-pilot and the healthyLIFE pilot (13),(14). The main objective of the present nationwide study is to look at the changes over time of participants in the behavioural change phase of the CooL-intervention (i.e., the first 8 months of CooL, which takes 24 months in total) on the topics of health perception, self-mastery, dietary intake, physical activity, alcohol use, smoking, sleep, stress management and anthropometrics.

The COVID-19 pandemic entered the Netherlands in February 2020, resulting in stringent COVID-19 measures that came into effect from March 2020 onwards. Obesity is considered a risk factor for a COVID-19 infection but also a risk factor for a more severe disease course resulting in higher mortality rates (15),(16). Dutch and international studies found that 70–90 percent of all COVID-19 patients admitted to Intensive Care Units with respiratory failure were overweight (17),(18). The immune system of patients with obesity is less capable of fighting viruses and bacteria. Lifestyle improvements lead to improvements in the immune system (19), which is an additional reason for deployment of the CLI for overweight people.

We expected the pandemic, and the measures aimed to curb it, to have an impact on the CLI-participants (20). As the severity of the disease course increased for overweight patients, it led to more stress in this high-risk population (21). The COVID-19 pandemic resulted for some people in a higher sense of urgency to start with a weight reduction program. Others, on the other hand, were hesitant to attend group meetings due to their high-risk profile related to a potential COVID-19 infection. The consequences of the COVID-19 restrictions such as a temporary curfew, closing (sports) facilities, working at home and wearing face masks in public areas led to feelings of loneliness but also impacted lifestyle routines (21). In addition, CLIs were initially temporarily suspended, pending guidelines on restricted human contact. Some CLI-groups were permanently closed down, others restarted in digital modus, providing additional challenges for both coaches and participants. COVID-19 shifted priority for caretakers and participants as there were shortages of staff due to sickness or deployment in more critical roles, impacting availability and attendance of (digital) CLI-sessions (22).

The objective of this study is to investigate the effect of COVID-19 implications and restrictions on the changes over time of participants after eight months of the CooL-intervention in perceptions, behaviours and anthropometrics.

CooL-intervention

The CooL-intervention aims for higher perceived quality of life, healthier eating habits (including a focus on healthy food choices, food quantities and eating with attention), more physical activity, less sedentary behaviour, attention for high quality sleep and relaxation, and positive changes in physical outcomes such as weight, BMI and waist circumference. CooL includes an intake (1 hour), a behavioural change phase of eight months (phase 1) with a follow-up phase of sixteen months (phase 2). The intervention consists of a combination of individual sessions (six hours in total) and group sessions (1,5 hours each). Phase 1 and phase 2 both include eight group sessions resulting in a higher density of sessions in phase 1 compared to phase 2 (13).

The CooL-intervention is an open CLI, which means that CooL has no strict protocol. Instead, it allows CooL-coaches to adapt the intervention to their target audience and context, within certain boundaries and restrictions. Participants pursue a predefined set of final objectives on knowledge and skills, supported by the coach who secures the main effective elements (e.g., goal setting, mobilizing social support, positive psychology, self-management and self-monitoring) of the CooL-intervention in implementation (13). The CooL-coaches are trained and licensed professionals who coach participants to take responsibility for their personal lifestyle changes by addressing motivation, personal objectives and behavioural change. Participants are stimulated and supported towards more self-steering and self-management by identifying, mapping and putting personal health related behaviour into action. The main objective is to coach and activate participants to a sustained healthier lifestyle in line with their individual needs and personal goals.

CooL-intervention during COVID-19

The COVID-19 implications and restrictions resulted in adaptations in the way CooL was offered to participants: some participants finalized the first eight months of CooL completely before COVID-19 broke out in the Netherlands, others participated in CooL during the COVID-19 pandemic and measures. The first infection was detected in the Netherlands on February 27th 2020, the first regional restrictions were imposed on March 6th and the 'intelligent lockdown' (a semi-lockdown with free human movement but restricted human contact) was introduced as of March 23th (23). We used a cut-off date of April 1st 2020, as participants finishing phase 1 of CooL before this date will have suffered limited to no impact on their lifestyle which cannot be guaranteed for participants finishing phase 1 of CooL after April 1st 2020. By means of the cut-off date we distinguished between participants that were potentially impacted by COVID-19 while participating in CooL and participants that were not impacted by COVID-19.

The way in which CooL was offered, changed during the COVID-19 pandemic. These changes were inventoried by a survey among both CooL-coaches and CooL-participants and by adding questions related to COVID-19 to the existing CooL outcome measurements. We collected information on the initiation of CooL during COVID-19, i.e. a digital start or a physical (face-to-face) start, and on the continuation mode of the sessions.

The open character of CooL provided ample opportunity for CooL-coaches to make adaptations to the content of the intervention, e.g. providing room for pressing topics like COVID-19 or COVID-19-related stress. In addition, the temporary extension in the CLI regulations in terms of health insurance made it possible to offer CooL digitally instead of via face-to-face contact only (24).

Observations from daily practice showed that COVID-19 resulted in higher dropout rates, resulting in financial consequences for the coaches and motivational challenges on the remaining group members and the coach. Some CooL-coaches completely quit executing CooL due to uncertainty, loss of motivation and/ or resistance to online coaching. Others decided to start up CooL, as COVID-19 caused an income drop for self-employed coaches and the CLI offered a basic and stable income. This observed impact of COVID-19 on coaches and participants of CooL, gave rise to the initiation of this study.

Study design and population

As CooL is part of regular health care, a control group receiving no treatment would be unethical, making a descriptive case series study the most appropriate study design in the Dutch context. The participants, all Dutch-speaking adults living in the Netherlands, were included from November 2018 until October 2021 at different locations throughout the Netherlands. Almost all participants met the inclusion criteria for participating in a CLI. In some cases (n = 5, 0.3%), BMI at baseline was below the inclusion threshold, potentially due to lifestyle changes in the time between participant’s application and the start of CooL. Since the waist circumference of these participants was above the threshold for inclusion, these cases were included.

Data collection

We used a questionnaire and anthropometric measurements to collect a broad set of data. The questionnaire was based on existing validated questionnaires. The outcome measures we collected can be divided into the categories anthropometrics (i.e. weight/BMI and waist circumference), control and support (i.e. self-mastery and social support), physical activity (i.e. sedentary time and active minutes), diet attentiveness, alcohol use and smoking, perceived fitness (i.e. perceived health, perceived fitness and impact of stress on daily functioning), sleep and stress.

During the course of the study, the questionnaire was extended with additional questions covering changes in context (e.g. COVID-19) and it was adjusted with textual simplifications in both questions and answers preserving the original essence as much as possible.

Data were collected at three time points during the CooL-intervention: at the beginning of the intervention, during the intake (T0); after 32 weeks, at completion of phase 1 of the intervention (T1); and after 24 months, at completion of the intervention (T2). The data from T2 were not yet available at the time of the analysis and will be included in a follow-up article.

Demographics

At baseline, participants were asked to report their personal characteristics such as gender, date of birth, country of birth and highest completed education, marital status, living situation and occupational status. Educational level was categorized as low (i.e., no education or primary education), intermediate (e.g., secondary education), and high (e.g., tertiary education) according to the definitions of the Dutch Central Bureau of Statistics (25). The living situation was divided into living together with someone (married or cohabiting) with or without kids and living alone (divorced, unmarried or widowed) with or without kids. The occupational status was categorized as: working (paid work, voluntary work or self-employed) and not working (homemaker, unemployed/job seeker, retired/in early retirement, disabled or student). Country of birth was categorized into Dutch or non-Dutch.

Anthropometrics

Under normal conditions anthropometric data (weight, length and waist circumference) are measured by the CooL-coaches with professional equipment according to the guidelines provided by the Dutch Association of General Practitioners (Dutch: Nederlands Huisartsen Genootschap, NHG) (26). Body weight (kg) was measured in kilogram, rounded off the nearest decimal. Height (m) was measured to the nearest centimeter without shoes. Waist circumference measurements were obtained to the nearest centimeter with a tape measure. As COVID-19 restrictions could have changed the measurement method, additional information, gathered from the CooL-coaches that were the main data suppliers (representing data of 490 participants), confirmed that in general, physical measurements took place either by the coach or on a distance of 1.5 meters under direct supervision of the coach.

Control and support

The self-mastery questions in the questionnaire were based on the short version of the Pearlin Mastery Scale using four questions (for example “I have little control over the things that happen to me”) and a 5-point Likert scale ranging from strongly agree (1) to strongly disagree (5) (27). To identify social support, we questioned the perceived support of close ones using a 5-point Likert scale ranging from no support at all (1) to a lot of support (5).

Physical activity

The outcome measurements on physical activity, diet and perceived fitness were defined in cooperation with the Dutch Association of Lifestyle coaches (BLCN) with the objective to capture the essence and map the desired outcomes of lifestyle coaching in a minimum set of questions. Physical activity used questions on sedentary behaviour, both on most and least active days (“What is the average number of hours you spent sitting on the day of the week you sit the most?”) and the number of physical activity minutes per day (“What is the average minutes per day that you are physically active (in minimum bouts of 10 minutes)?”).

Diet attentiveness, alcohol use and smoking

We defined questions on dietary attentiveness, in line with the input of the BLCN, based on the knowledge that deliberate behaviour changes start with awareness. We used questions on the awareness of participants towards meal composition and meal quantities and awareness during the actual consumption of food using a 5-point Likert scale from very little attention (1) to a lot of attention (5). In addition, the number of units of alcohol consumed, and units smoked per day was asked with a numerical value.

Perceived fitness

Perceived fitness existed of questions, in line with the input of the BLCN, on perceived fitness when waking up and during the day, the impact of stress on daily functioning and on perceived health (i.e. feeling good about oneself, the extent of self-care invested and the perception of one’s general health). Questions were answered using a 5-point Likert scale, ranging from not good at all (1) to very good (5).

Sleep

We defined a specific set of questions around the sub-constructs: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication and daytime dysfunction, analogous to the validated and widely used PSQI-questionnaire (28). Each subconstruct was covered by one or two question(s) using a numerical value or a 4-point Likert scale, ranging from ‘never’ (1) to ‘three times per week or more frequently’ (4).

Stress

For stress, the validated Perceived Stress Scale questionnaire was used, which exists of ten questions using a 5-point Likert scale from never (1) to always (5) (29).

COVID-19

We used a brief questionnaire for the lifestyle coach in retrospect to collect data on the way CooL was offered during COVID-19. The questions were related to the start date of the intervention derived from the date of the intake, the way the intervention was offered and the mode in which the intervention was started (e.g. starting in face-to-face mode versus digital mode). We used four categories to distinguish the way the intervention was offered: only face-to-face sessions, only digital sessions, a combination with more face-to face than digital sessions and a combination with more digital than face-to-face sessions.

Analyses

As a first step, we recoded some of the variables to facilitate interpretation in the sense that a higher/positive score refers to a desirable trend and lower/negative scoring to an undesirable trend in the variable. For constructs based on validated questionnaires (i.e. self-mastery, sleep and stress) we adopted the accompanying approach without recoding. Secondly, we performed an exploratory factor analysis using R software and calculated McDonald’s omega to assess the internal structure of items regarding several constructs such as perceived health, self-mastery, sleep and stress. These analyses justified summarizing all lifestyle constructs by item score means.

For all items and constructs, we ran descriptive analyses (e.g., means, standard deviations, distributions). Changes over time in outcome measures were analysed using paired t-tests (T0 versus T1). Effect sizes were calculated and interpreted in accordance with Lipsey’s guidelines for each pair of outcomes, i.e. an effect size smaller than 0.32 is considered small, an effect size between 0.33 and 0.55 is considered medium and an effect size above 0.56 is considered large (30). To improve comprehensibility effect sizes are represented such that positive values represent change in the desired direction whereas negative values represent change in an undesired direction.

To be considered successful, the target for the CLI (including CooL) is a 5% weight loss, as set by the Dutch Partnership Overweight (Dutch: PON), an advisory body for the Dutch government on obesity related health issues. We categorized the outcomes on weight: 5% weight loss or more, between 0 and 5% weight loss, weight stabilization or weight gain to map the percentage of participants with weight loss.

Next, we split the dataset in two subgroups: pre-COVID and during-COVID to enable comparison of differences from T0 to T1 between participants that were potentially impacted by COVID-19 and those that were not impacted by COVID-19. For all these differences we performed independent T-tests comparing subgroups. All T-tests were performed using SPSS- software (version 27). Missing data were excluded from the statistical analyses, because these cases could not be included in the calculation of the differences between T0 and T1.

Ethics

This study was submitted to and approved by the Research Ethics Committee of the Faculty of Health, Medicine and Life Sciences of Maastricht University (FHML-REC/2019/073). All participants gave their informed consent for their anonymised personal data to be used for research purposes.

Funding

No funding was provided for this research.

Participants demographics

A total of 1824 adults participated between November 2018 and October 2021. For each subset the amount of missing data differed per item per time of measurement.

Table 1. Demographics of the participants (N=1824)

Category	Demographic	Percentage of participants in dataset
Gender	Male	28%
	Female	72%
Age	Until 35 years	11%
	35 – 44 years	16%
	45- 54	29%
	55 – 64 years	28%
	65+	16%
Living situation	Single	18%
	Single parent	7%
	Living together with kids	43%
	Living together without kids	28%
	Other	4%
Country of birth	Dutch	95%
	Non-Dutch	5%
Working situation	Employed	75%
	Unemployed	25%
Education	Lower level	28%
	Intermediate level	39%
	Higher level	33%

Of all participants a total of 28% were male and 72% female. This ratio is in line with the data from the national CLI-monitor (32). Most participants (95%) were born in the Netherlands. Two third of the participants had a lower or intermediate level of education; 25% did not have a steady job (anymore) and over 70% of the participants were living together with a partner (Table 1).

Subgroups CooL during COVID-19

From roughly a quarter of the participants (24%), we received information on the way CooL was offered during COVID-19. Eighty percent of the participants started in face-to-face (physical) mode whereas 20% started digitally. Almost all participants received CooL through a combination of physical and digital sessions. Most participants received more physical than digital sessions (83% of the physical starters, 52% of the digital starters), followed by more digital than physical sessions (14% of the physical starters, 47% of the digital starters), 2% of all participants received physical sessions only and 0.5% digital sessions only.

The limited available data on the way CooL was offered during COVID-19, makes it impossible to draw strong conclusions on the differences in outcomes of subgroups based on the start mode of CooL and on the ratio between face-to-face and digital sessions. However, we could define subgroups of participants that were potentially impacted by COVID-19 and participants that were not, based on the date the intervention started and derived from that, the date the participants finished phase 1 of CooL (Table 2).

A total of 120 participants finished phase 1 before April 1^st2020. Most participants (n=1667) finished the first phase of CooL after April 1^st2020, which implies that those participants were potentially affected by the COVID-19 implications and measures when participating in CooL.

Table 2. Number of participants per subgroup.

Subgroup	N
Runtime pre-COVID (T1 before April 1^st 2020)	120
Runtime during COVID (T1 after April 1^st 2020)	1667
No information on runtime	37
TOTAL	1824

Results on all items and constructs

In Table 3 all outcome measurements pre and during COVID-19 are presented.

Table 3. Results on all outcome measurements pre and during COVID-19.

		Full sample (N=1824)				Pre-COVID-19 (n=120) versus during COVID-19 (n=1667)
Category	Construct/ factor	T0 M (sd)	T1 M (sd)	∆ T0-T1 [95% CI]	Effect size T0-T1**	Pre COVID- ∆ TOT1 (sd)	During COVID- ∆ TOT1 (sd)	T-test Pre versus During COVID on ∆ T0T1 (p-value)
Anthropometrics	Weight	106.38 (18.50)	103.01 (18.37)	-3.44 [-3.73; -3.15]*	0.57	-3.68 (6.71)	-3.45 (5.85)	0.98
	BMI	35.97 (5.49)	34.80 (5.58)	-1.16 [-1.26; -1.06]*	0.58	-1.29 (2.40)	-1.17 (1.96)	0.92
	Waist circumference	116.30 (13.24)	112.35 (14.27)	-4.21 [-4.65; -3.77]*	0.50	-3.83 (5.93)	-4.23 (8.50)	0.27
Control & support	Self-mastery	2.54 (0.75)	2.48 (0.69)	-0.07 [-0.11; -0.03]*	0.10	-0.29 (0.74)	-0.06 (0.70)	0.01*
	Social support	3.77 (0.94)	3.73 (0.90)	0.03 [-0.02; 0.08]	0.03	0.15 (1.01)	-0.04 (0.93)	0.06
Physical activity	Sedentary time (least active)	9.56 (3.50)	8.77 (3.36)	-0.81 [-0.98; -0.65]*	0.25	0.05 (4.45)	-0.83 (3.16)	0.02*
	Sedentary time (most active)	6.31 (3.40)	5.79 (3.14)	-0.57 [-0.74; -0.41]*	0.18	0.41 (4.41)	-0.64 (3.10)	0.01*
	Physical active minutes	95.24(112.04)	108.37 (111.13)	14.56 [9.33; 19.79]*	0.15	8.97 (96.54)	14.91 (99.40)	0.63
Diet attentiveness	Meal composition	3.11 (0.98)	3.53 (0.83)	0.43 [0.38; 0.48]*	0.43	0.56 (0.92)	0.43 (1.00)	0.26
	Amounts of food	2.81 (0.97)	3.43 (0.83)	0.62 [0.57; 0.68]*	0.58	0.77 (0.97)	0.62 (1.10)	0.18
	Attentive to consuming	2.84 (1.00)	3.25 (0.91)	0.41 [0.36; 0.46]*	0.39	0.29 (1.07)	0.41 (1.03)	0.28
	Alcohol consumption	1.41 (2.02)	1.04 (1.59)	-0.32 [-0.41; -0.25]*	0.19	-0.10 (1.45)	-0.34 (1.68)	0.12
	Smoking	0.75 (3.61)	0.68 (3.24)	-0.05 [-0.15; 0.06]	0.02	-0.21 (2.24)	-0.05 (2.18)	0.45
Perceived fitness	Perceived health	9.07 (2.22)	10.21 (2.07)	1.15 [1.04; 1.26]*	0.50	1.81 (2.63)	1.12 (2.26)	0.01*
	Fitness (waking)	2.38 (0.91)	2.63 (0.80)	0.26 [0.22; 0.31]*	0.28	0.54 (0.97)	0.25 (0.95)	<0.00*
	Fitness (daytime)	2.47 (0.85)	2.65 (0.79)	0.18 [0.14; 0.23]*	0.19	0.45 (1.03)	0.17 (0.97)	0.01*
	Impact stress (daily)	2.21 (0.94)	2.24 (0.89)	0.05 [0.00; 0.09]*	0.05	0.28 (0.90)	0.03 (0.95)	0.02*
Sleep	Sleep (summary)	7.13 (4.12)	6.09 (3.81)	-1.10 [-1.30; -0.91]*	0.30	-1.44 (3.22)	-1.10 (3.70)	0.42
Stress	Stress (summary)	14.24 (6.67)	13.07 (6.30)	-1.37 [-1.69; -1.05]*	0.23	-3.48 (6.48)	-1.36 (5.80)	<0.00*

*p<0.05

**Positive effect size representing an effect in desired direction, negative effect size representing an effect in undesired direction

Anthropometrics

Weight, BMI and waist circumference all showed a decrease after eight months (T1) compared to baseline (T0). The BMI of the participants was on average 35.97 at T0 and decreased with 1.16 BMI-points at T1. The average weight loss was 3.4 kg at T1, corresponding to a 3.2% average weight loss per participant after eight months. In total 72% of the participants lost weight. Twentynine percent lost more than 5% at T1. The average waist circumference of the participants decreased from 116.6 cm at T0 to 112.4 cm at T1. The change in waist circumference demonstrated a medium effect size at T1, whereas BMI and weight showed a large effect size at T1.

Participation in CooL during versus pre COVID-19 did not show a significant difference on weight, BMI or waist circumference of the participants, indicating that despite the pandemic, similar effects of the intervention were found.

Control and support

Self-mastery showed a decrease at T1 compared to baseline with a small effect size in the desired direction. Social support showed no change over time.

Differences in outcomes between participants pre versus during COVID-19 were present for self-mastery with a larger effect for participants that participated pre COVID-19.

Physical activity

Sedentary time decreased at T1 both for least and most active days of the week: participants sat on average 48 minutes less on least active and 34 minutes less on most active days compared to baseline. The average daily active minutes (in minimum bouts of 10 minutes) increased from 94 minutes at T0 to on average 108 minutes at T1. The effect size on both sedentary and active time was small.

Comparing the outcomes pre and during COVID-19: participants during COVID-19 showed a decrease in sedentary time compared to baseline whereas participants before COVID-19 showed a small increase. No difference between both subgroups could be detected on physical active minutes.

Diet attentiveness, alcohol and smoking

Over time the participants showed an increase in attentiveness for meal composition, awareness for the amounts of food selected and attentiveness when consuming food. In addition, the participants showed a decrease in alcohol consumption. The effect size on attentiveness for meal composition and consuming food was medium-sized, the effect size for the amounts of food selected was large and the effect size for alcohol consumption was small when comparing baseline to T1. Smoking showed no effect on T1 compared to baseline.

The outcomes of participants pre COVID-19 versus during COVID-19 showed no difference on the diet related outcomes, alcohol consumption or smoking.

Perceived fitness

The perceived fitness factors perceived health, feeling fit when waking up, feeling fit during the day and the impact of stress on daily functioning all showed an effect in the desired direction with a small effect size, except for perceived health which showed a medium effect size at T1.

The subgroup comparison showed that the effects at T1 compared to baseline were larger for participants pre COVID-19 compared to during COVID-19 on all perceived fitness factors.

Sleep and stress

The constructs sleep and stress both showed a decrease on T1 compared to baseline with a small effect in the desired direction.

Stress perception of participants in CooL prior to COVID-19 restrictions showed a larger decrease in stress compared to the stress perception of participants during COVID-19. No differences were found between both subgroups on sleep.

This study investigated changes in various outcomes after eight months of the CooL-intervention. Overall, the analyses showed positive changes compared to baseline. The largest effect sizes were found on weight, waist circumference, BMI, perceived health and the awareness around diet (i.e. attentiveness for diet, amount of food and consuming food). Changes in behaviour and perceived fitness varied between small and medium effect size, whereas changes in anthropometrics had a medium to large effect size. It is plausible that these small behavioural changes together sum up to medium and large-sized changes in anthropometric outcomes and perceived health. The results indicate that the COVID-19 pandemic impacted negatively on changes in self-mastery, perceived fitness and stress, but not on anthropometric outcomes, diet, sleep or social support.

Encouraging participants to take responsibility for their personal lifestyle is an essential element of CooL. Participants prioritize their health-related behaviours and define personal actions. The consequence of this set-up is that all participants start working on a behavioural aspect of their choice, leading to average changes when looking at a population level. Note that the timeframe of this study only covers the first eight months of the intervention, implying that participants might not yet have initiated changes in all health-related behavioural domains.

To explore the assumption that small behavioural changes sum up to medium and large effects in anthropometrics, we performed a post-hoc sensitivity analysis to compare the trend (desired, neutral or undesired) in changes in behaviour components to the trend (desired, neutral or undesired) in changes in the outcome components weight/BMI and waist circumference. This sensitivity analysis showed that in general the trend in all behaviour components showed a similar pattern as the trend in anthropometric outcomes, giving support to the assumption that the behavioural changes correlate with the anthropometric changes. In short, more physical active minutes, more attentiveness to diet and improved stress management are related to weight loss in CooL. Two exceptions are smoking and sleep: in many cases people that quit smoking, gain weight during the first few months of abstinence (33) and the relation between sleep-related behaviour and weight is likely to be more indirect (i.e. via hormonal pathways and other behaviours) (12).

The average weight loss per participant was 3.2%, with 29% of the participants losing 5% or more. This corresponds with a decrease of 1.16 points in BMI and an average decrease of 3.4 kg after the first eight months of CooL. Compared to previous research on the CooL-pilot (13), HealthyLIFE-pilot (14) (with respectively an average decrease in weight of 2.3 kg and 2.4 kg) and research on similar interventions (34), (35), (36), these results are promising. Future research on the 2-year results is needed to determine the effect of the CooL-intervention on the total duration.

The results of the subgroup analyses show that participation during COVID-19 has an effect on part of the outcome measures of CooL. These finding are partly in line with previous research: the outcome of the CooL-participants on stress during COVID-19, i.e. a larger decrease of perceived stress when participating prior to COVID-19, is in line with the findings of Ammar (37): they identified a negative effect on both mental-wellbeing and on mood and feelings during COVID-19. Especially vulnerable populations have been found to show an increase in stress (38), (39). For alcohol usage and smoking two opposite outcomes were seen during COVID-19: an increase due to distress or boredom and a decrease in usage linked to prevention and health withstanding the threat of COVID-19 or limited access and resources. On population level increases in alcohol usage for some people even out with decreases in alcohol usage for others, leading to an average at population-level close to zero (40). A similar reasoning for smoking could explain that no effect on alcohol and smoking was seen for the CooL-participants during COVID-19 (41). However, the comparison of this intervention study with active participants with population-level observational studies should be done with great caution.

There are also several findings that are not in line with previous research: firstly, research on the effect of COVID-19 on sleep in several European countries show delayed sleep timing, more time spent in bed and impaired sleep quality. It also shows large individual differences in perceived sleep quality mainly depending on pre-pandemic sleep quality. In general, negative affect and feelings of worry linked to COVID-19 restrictions, were associated with changes in sleep quality (42), (43). In contrast, the present study showed that the improvements in perceived sleep quality did not differ prior versus during COVID-19.

Secondly, other studies on the impact of COVID-19 on lifestyle-related behaviour have shown that most health behaviours were largely affected by the pandemic and its related measures. Regarding diet, Huber et al. (44) showed an increase in food consumption, especially for overweight people. Furthermore, the majority of studies have shown a decrease in physical activity and an increase in sedentary behaviour during COVID-19 lockdowns across several populations (45), (46), (23). The CooL subgroup analysis showed no difference between the runtime of CooL prior versus during COVID-19 for both diet and physical activity. The changes in sedentary time were even more desirable for participants in CooL during the pandemic. In times of a major pandemic the consistency and/or small improvements in behaviour are likely to be a huge win.

The effect of CooL on the three anthropometric outcomes was not affected by COVID-19 as the subgroup analyses showed no difference between participation in CooL pre or during COVID-19. This is a striking result given the outcomes of previous research on this topic: two studies on weight change during COVID-19 pandemic indicated an average weight gain of 1.5 to 2 kg (47), (48), whereas an online questionnaire in The Netherlands even showed an average weight gain of 5.6 kilos (49). Overall, the results of this study indicate that the effect on the anthropometric outcomes of the CooL-participants were not affected by COVID-19. Participating in the CooL-intervention may thus have protected against relapsing to unhealthier behaviour despite a decreased sense of self-mastery and increased stress.

Limitations and strengths

During the time of the study the questionnaire was subject to minor revisions. We intended to keep the scope of the questions and answers similar for all versions, but we cannot rule out any effect on the study. However, as with any observational study, differences in outcomes could also be due to differences in demographics, zeitgeist and the emergence of COVID-19. The sudden emergence of COVID-19 was unforeseen and can be considered a limitation of the study as it impacted the intervention and outcomes in many ways. It can, however, also be regarded as an opportunity to study the effects of a large-scale health promotion intervention during a pandemic. However, the lack of a control group inhibits us to draw strong conclusions on the effectiveness of the intervention. Results indicate changes over time, but inferences regarding intervention effectiveness need to be interpreted with caution.

Motivation was questioned using a scale derived from Self-Determination Theory with six questions. The exploratory factor analysis did not justify summarizing the motivational items in one construct by item score means. Consequently, we looked at these motivation items separately instead of using one summarizing construct, in line with Chemolli and Gagné (50). However, this approach led to uninterpretable results. Anecdotal evidence collected by feedback from participants and coaches indicated that the motivational questions caused confusion and were considered difficult to interpret for participants. This led to a drastic revision of the measurement of this construct in the questionnaire for future research.

Despite all attempts to collect additional data, we did not receive enough data to draw strong conclusions on the different ways of implementing CooL during COVID-19 (e.g. digital versus physical contact and starting in digital versus face-to-face mode) and only on whether it was implemented before or during COVID-19. To draw strong conclusions on the different ways of implementing CooL in digital mode, more data is needed on different implementation modes of CooL. A total of 29 participants in the overall dataset could not be assigned to the subgroups pre or during COVID-19 leading to slightly deviating average outcomes in the subsamples.

After eight months of CooL, large effect sizes on changes in anthropometrics and perceived health were found, irrespective of participation during the COVID-19 pandemic. Participating in the CooL-intervention may have protected against engaging in unhealthier behaviours during the pandemic, despite a decreased sense of self-mastery and increased stress. The results support the lifestyle coaching approach that small changes in multiple behaviours can synergistically contribute to better (perceived) health and health-related outcomes.

BLCN: Beroepsvereniging Leefstijlcoaches Nederland

BMI: Body Mass Index

CLI: Combined Lifestyle Intervention

CooL: Coaching op Leefstijl

COVID-19: Corona virus disease 19

FHML-REC: Ethics Review Committee of the Faculty of Health, Medicine and Life Sciences

NHG: Nederlands Huisarts Genootschap

PON: Partnerschap Overgewicht Nederland

PSQI: Pittsburgh Sleep Quality Index

RIVM: Rijksinstituut voor Volksgezondheid en Milieu

SPSS: Statistical Package for the Social Sciences

Ethics approval and consent to participate

This study was conducted according to the guidelines of the Declaration of Helsinki. This study was submitted to and approved by the Research Ethics Committee of the Faculty of Health, Medicine and Life Sciences of Maastricht University (FHML-REC/2019/073). Informed consent was obtained from all subjects involved in this study. All participants in CooL are adults except one minor who started the intervention at the age of 16. In the Netherlands adolescents from the age of 16, have the legal right to decide for themselves on medical treatments as they have the same patient rights as adults.

Consent for publication

Not applicable.

Availability of data and materials

The datasets generated and/or analysed during the current study are not publicly available because the informed consent statement to using data at the individual level was limited to the authors of this article and are only available from the corresponding author on reasonable request.

Competing interests

Not applicable for S.K. and R.C.. Both main authors (E.J. and N.P.) are co-owner of the CooL-intervention.

Funding

Not applicable

Authors' contributions

Conceptualization, N.P., E.J., R.C. and S.K.;

Methodology, N.P., E.J., R.C. and S.K.;

Validation, R.C. and S.K.;

Formal Analysis, N.P., E.J. and R.C;

Investigation, N.P. and E.J.;

Data Curation, N.P. and E.J.;

Writing—Original Draft Preparation, N.P. and E.J.;

Writing—Review and Editing R.C., and S.K.;

Visualization, N.P. and E.J.;

Funding Acquisition, not applicable.

Both E.J. and N.P. contributed equally to the study.

All authors have read and agreed to the published version of the manuscript.

Acknowledgements

The authors like to thank the CooL-coaches and the CooL-participants for their efforts to make this research possible.

Authors' information (optional)

Not applicable

Centrum Gezondheid en Maatschappij van het Rijksinstituut voor Volksgezondheid en Milieu. Volwassenen met overgewicht en obesitas 2021. 2023, January 19 [Available from: https://www.volksgezondheidenzorg.info/onderwerp/overgewicht/cijfers-context/huidige-situatie#node-overgewicht-volwassenen.
James WPT. The fundamental drivers of the obesity epidemic. Obesity Reviews. 2008;9(s1):6-13.
Overgewicht en obesitas. Den Haag: Gezondheidsraad 2003
Boeing H. Obesity and cancer--the update 2013. Best practice & research Clinical endocrinology & metabolism. 2013;27(2):219-27.
Martin-Rodriguez E, Guillen-Grima F, Martí A, Brugos-Larumbe A. Comorbidity associated with obesity in a large population: The APNA study. Obesity research & clinical practice. 2015;9(5):435-47.
Overgewicht: leeftijd en geslacht volwassenen Bilthoven: RIVM; 2023 [cited 2023 February 13]. Available from: https://www.vzinfo.nl/overgewicht/leeftijd-geslacht.
Luppino FS, de Wit LM, Bouvy PF, Stijnen T, Cuijpers P, Penninx BW, et al. Overweight, obesity, and depression: a systematic review and meta-analysis of longitudinal studies. Archives of general psychiatry. 2010;67(3):220-9.
Taylor VHAPMDP, Forhan MAPP, Vigod SNAPMD, McIntyre RSPMD, Morrison KMAPMD. The impact of obesity on quality of life. Best Practice & Research Clinical Endocrinology & Metabolism. 2013;27(2):139-46.
Obesity and overweight: World Health Organization 2021, June 9. [cited 2023 January 24]. Available from: https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight.
Bos V, van Dale D, Leenaars K. Werkzame elementen van Gecombineerde Leefstijlinterventies. Rijksinstituut voor Volksgezondheid en Milieu; 2019.
van der Valk ES, Savas M, van Rossum EFC. Stress and Obesity: Are There More Susceptible Individuals? Current Obesity Reports. 2018;7(2):193-203.
Lee JH, Cho J. Sleep and Obesity. Sleep Medicine Clinics. 2022;17(1):111-6.
van Rinsum C, Gerards S, Rutten G, Philippens N, Janssen E, Winkens B, et al. The Coaching on Lifestyle (CooL) Intervention for Overweight and Obesity: A Longitudinal Study into Participants' Lifestyle Changes. International journal of environmental research and public health. 2018;15(4).
Philippens N, Janssen E, Verjans-Janssen S, Kremers S, Crutzen R. HealthyLIFE, a Combined Lifestyle Intervention for Overweight and Obese Adults: A Descriptive Case Series Study. International journal of environmental research and public health. 2021;18(22):11861.
Jayawardena R, Jeyakumar DT, Misra A, Hills AP, Ranasinghe P. Obesity: A potential risk factor for infection and mortality in the current COVID-19 epidemic. Diabetes & Metabolic Syndrome: Clinical Research & Reviews. 2020;14(6):2199-203.
de Frel DL, Atsma DE, Pijl H, Seidell JC, Leenen PJM, Dik WA, et al. The Impact of Obesity and Lifestyle on the Immune System and Susceptibility to Infections Such as COVID-19. Frontiers in Nutrition. 2020;7.
van der Voort PHJ, Moser J, Zandstra DF, Muller Kobold AC, Knoester M, Calkhoven CF, et al. Leptin levels in SARS-CoV-2 infection related respiratory failure: A cross-sectional study and a pathophysiological framework on the role of fat tissue. Heliyon. 2020;6(8):e04696.
Stefan N, Birkenfeld AL, Schulze MB, Ludwig DS. Obesity and impaired metabolic health in patients with COVID-19. Nature Reviews Endocrinology. 2020;16(7):341-2.
van der Zalm IJB, van der Valk ES, Wester VL, Nagtzaam NMA, van Rossum EFC, Leenen PJM, et al. Obesity-associated T-cell and macrophage activation improve partly after a lifestyle intervention. International Journal of Obesity. 2020;44(9):1838-50.
Klerk Md. Een jaar met corona: Ontwikkelingen in de maatschappelijke gevolgen van corona. Sociaal en Cultureel Planbureau, Den Haag; 2021.
Grannell A, le Roux CW, McGillicuddy D. “I am terrified of something happening to me” The lived experience of people with obesity during the COVID-19 pandemic. Clinical Obesity. 2020;10(6):e12406.
Kemper P, . Impact coronapandemie op preventie interventies en integrale samenwerking. Rijksinstituut voor Volksgezondheid en Milieu; 2022.
de Haas M, Faber R, Hamersma M. How COVID-19 and the Dutch ‘intelligent lockdown’ change activities, work and travel behaviour: Evidence from longitudinal data in the Netherlands. Transportation Research Interdisciplinary Perspectives. 2020;6:100150.
De gecombineerde leefstijlinterventie tijdens de coronacrisis. Zeist: Zorgverzekeraars Nederland 2020 [cited 2023 January 12]. Available from: https://assets.zn.nl/p/32768/files/De%20gecombineerde%20leefstijlinterventie%20tijdens%20de%20coronacrisis.pdf.
Opleidingsniveau Centraal Bureau voor de Statistiek [cited 2023 January 12]. Available from: https://www.cbs.nl/nl-nl/nieuws/2017/22/vooral-hoogopgeleiden-roken-minder/opleidingsniveau.
Protocol BMI en middelomtrek meten: Nederlands Huisartsen Genootschap 2016 [cited 2023 January 12]. Available from: https://www.nhg.org/downloads/protocol-bmi-en-middelomtrek-meten#:~:text=Bij%20een%20BMI%20die%20rond,risico%20op%20morbiditeit%20duidelijk%20verhoogd.
Eklund M, Erlandsson L-K, Hagell P. Psychometric properties of a Swedish version of the Pearlin Mastery Scale in people with mental illness and healthy people. Nordic Journal of Psychiatry. 2012;66(6):380-8.
Buysse DJ, Reynolds CF, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh sleep quality index: A new instrument for psychiatric practice and research. Psychiatry Research. 1989;28(2):193-213.
Cohen S, Kamarck T, Mermelstein R. A Global Measure of Perceived Stress. Journal of Health and Social Behavior. 1983;24(4):385-96.
Lipsey MW. Design sensitivity : statistical power for experimental research. Newbury Park, CA: Sage Publications; 1990.
Wet medisch-wetenschappelijk onderzoek met mensen: Overheid.nl Wettenbank; [cited 2023 January 19]. Available from: https://wetten.overheid.nl/jci1.3:c:BWBR0009408&z=2021-07-01&g=2021-07-01.
Oosterhoff M, de Weerdt A, Feenstra T, de Wit A. Jaarrapportage monitor GLI 2022. Stand van zaken gecombineerde leefstijlinterventie. Annual report – Monitor Combined lifestyle intervention 2022 Combined lifestyle intervention progress report: Rijksinstituut voor Volksgezondheid en Milieu RIVM; 2022.
Aubin H-J, Farley A, Lycett D, Lahmek P, Aveyard P. Weight gain in smokers after quitting cigarettes: meta-analysis. BMJ: British Medical Journal. 2012;345(7868):14.
Duijzer G, Haveman-Nies A, Jansen SC, Beek JT, van Bruggen R, Willink MGJ, et al. Effect and maintenance of the SLIMMER diabetes prevention lifestyle intervention in Dutch primary healthcare: a randomised controlled trial. Nutrition & diabetes. 2017;7(5):e268.
Schutte BA, Haveman-Nies A, Preller L. One-Year Results of the BeweegKuur Lifestyle Intervention Implemented in Dutch Primary Healthcare Settings. BioMed research international. 2015;2015:484823.
Mölenberg F, Mesch A, Burdorf A. Effect studie Samen Sportief in Beweging, een gecombineerde leefstijl interventie gericht op lagere sociaal economische groepen. Erasmus Medisch Centrum, Afdeling Maatschappelijke Gezondheidszorg; 2018, August.
Ammar A, Mueller P, Trabelsi K, Chtourou H, Boukhris O, Masmoudi L, et al. Psychological consequences of COVID-19 home confinement: The ECLB-COVID19 multicenter study. PloS one. 2020;15(11):e0240204.
COVID-19 and your mental health: Mayo Clinic [cited 2023 January 17]. Available from: https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/mental-health-covid-19/art-20482731
Manchia M, Gathier AW, Yapici-Eser H, Schmidt MV, de Quervain D, van Amelsvoort T, et al. The impact of the prolonged COVID-19 pandemic on stress resilience and mental health: A critical review across waves2022.
Roberts A, Rogers J, Mason R, Siriwardena AN, Hogue T, Whitley GA, et al. Alcohol and other substance use during the COVID-19 pandemic: A systematic review. Drug and Alcohol Dependence. 2021;229:109150.
Bommele J, Hopman P, Walters BH, Geboers C, Croes E, Fong GT, et al. The double-edged relationship between COVID-19 stress and smoking: Implications for smoking cessation. Tobacco Induced Diseases. 2020;18:1-5.
Cellini N, Conte F, De Rosa O, Giganti F, Malloggi S, Reyt M, et al. Changes in sleep timing and subjective sleep quality during the COVID-19 lockdown in Italy and Belgium: age, gender and working status as modulating factors. Sleep Medicine. 2021;77:112-9.
Kocevska D, Blanken TF, Van Someren EJW, Rösler L. Sleep quality during the COVID-19 pandemic: not one size fits all. Sleep Medicine. 2020;76:86-8.
Huber BC, Steffen J, Schlichtiger J, Brunner S. Altered nutrition behavior during COVID-19 pandemic lockdown in young adults. European Journal of Nutrition. 2021;60(5):2593-602.
Park AH, Zhong S, Yang H, Jeong J, Lee C. Impact of COVID-19 on physical activity: A rapid review. Journal of global health. 2022;12:05003.
Stockwell S, Trott M, Tully M, Shin J, Barnett Y, Butler L, et al. Changes in physical activity and sedentary behaviours from before to during the COVID-19 pandemic lockdown: a systematic review. BMJ open sport & exercise medicine. 2021;7(1):e000960.
Pellegrini M, Ponzo V, Rosato R, Scumaci E, Goitre I, Benso A, et al. Changes in weight and nutritional habits in adults with obesity during the “lockdown” period caused by the COVID-19 virus emergency. Nutrients. 2020;12(7):2016.
Biamonte E, Pegoraro F, Carrone F, Facchi I, Favacchio G, Lania AG, et al. Weight change and glycemic control in type 2 diabetes patients during COVID-19 pandemic: the lockdown effect. Endocrine. 2021;72(3):604-10.
Bailey P, Purcell S, Calvar J, Baverstock A. Diet and health under COVID-19. Ipsos; 2021.
Chemolli E, Gagné M. Evidence against the continuum structure underlying motivation measures derived from self-determination theory. Psychological Assessment. 2014;26(2):575-85.

Competing interest reported. Both main authors (E.J. and N.P.) are co-owner of the CooL-intervention. Not applicable for S.K. and R.C..

The combined lifestyle intervention CooL in times of COVID-19: a descriptive case series study

Status:

Journal Publication

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Abstract

Background

Methods

Results

Conclusion

1. Background

2. Methods

3. Results

4. Discussion

Limitations and strengths

5. Conclusions

6. Abbreviations

Declarations

References

Additional Declarations

Status:

Journal Publication

Version 1