Characteristics
Of the 60 participants enrolled in HDLS, six (10%) dropped out (IER+MED:4; DASH:2), with only one participant withdrawing from the study before the Week 1 follow-up call. Of the 54 participants completing HDLS, all 54 participants completed the Exit Questionnaire and 48 participants responded to the six-month post-intervention telephone interview. Of participants included in the current analysis, 29 (48.2%) were randomized to IER+MED and 30 (50.8%) to DASH (Table 1). The study participants were mostly women (69.5%), participants with high VAT (67.8%), and of Japanese ancestry (62.7%). Baseline characteristics were similar for the 59 participants included in this analysis, the 54 participants who completed the Week 12 visit and the 48 who completed the 6-month post-intervention survey.
Splitting data by median adherence, baseline characteristics were similar between dietary adherence groups and between physical activity adherence groups (Table 1). The largest differences in adherence were seen between ethnic groups. For dietary adherence, 71.4% (n=5) participants of Korean or Mixed Asian ancestry were in the low category. For physical activity adherence, 100% (n=7) of participants with Korean ancestry were in the low group, and 75% (n=6) of participants of Chinese ancestry were in the high adherence group.
Table 1. Baseline characteristics of participants (n=59) by self-rated adherence to dietary and physical activity prescriptions
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|
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Dietary adherence1,2
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Physical activity adherence2,3
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Characteristic
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All
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Low
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High
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Low
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High
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Study arm, n (%)4
|
|
|
|
|
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IER+MED5
|
29 (49.2)
|
14 (48.3)
|
15 (51.7)
|
12 (41.4)
|
17 (58.6)
|
DASH6
|
30 (50.8)
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17 (56.7)
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13 (43.3)
|
16 (53.3)
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14 (46.7)
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Sex, n (%)
|
|
|
|
|
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Men
|
18 (30.5)
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7 (38.9)
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11 (61.1)
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8 (44.4)
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10 (55.6)
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Women
|
41 (69.5)
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24 (58.5)
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17 (41.5)
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20 (48.8)
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21 (51.2)
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Visceral adipose tissue, n (%)
|
|
|
|
|
|
High7 (80 or 90 to < 150 cm2)
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40 (67.8)
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23 (57.5)
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17 (42.5)
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20 (50.0)
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20 (50.0)
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Very high (≥ 150 cm2)
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19 (32.2)
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8 (42.1)
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11 (57.9)
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8 (42.1)
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11 (57.9)
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Ethnicity, n (%)
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|
|
|
|
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Chinese
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8 (13.6)
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4 (50.0)
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4 (50.0)
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2 (25.0)
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6 (75.0)
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Japanese
|
37 (62.7)
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17 (45.9)
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20 (54.1)
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15 (40.5)
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22 (59.5)
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Korean
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7 (11.9)
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5 (71.4)
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2(28.6)
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7 (100.0)
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0 (0.0)
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Mixed Asian
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7 (11.9)
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5 (71.4)
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2 (28.6)
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4 (57.1)
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3 (42.9)
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Other Characteristics, mean ± SD
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|
|
|
|
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Age, y
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47.4 ± 5.1
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46.1 ± 5.3
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48.9 ± 4.4
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45.9 ± 5.7
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48.9 ± 4.0
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Weight, kg
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80.4 ± 12.4
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78.2 ± 11.4
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82.8 ± 13.4
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80.0 ± 11.3
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80.7 ± 13.4
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Body mass index, kg/m2
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30.7 ± 3.4
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30.2 ± 3.4
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31.2 ± 3.3
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30.5 ± 3.6
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31.0 ± 3.1
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1Self-rated dietary adherence ranging from zero being not at all to ten being following the plan very well, split by median adherence (7.3). 2Imputed values for missing adherence data. 3Self-rated physical activity adherence ranging from zero being not at all to ten being following the plan very well, split by median adherence (7.1). 4Column percentages for overall column and row percentages for data by self-rated adherence level. 5Intermittent energy restriction combined with a Mediterranean diet (IER+MED). 6Euenergetic Dietary Approaches to Stop Hypertension diet (DASH). 7Women at ≥80 cm2 and men at ≥90 cm2.
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Adherence
Overall, mean ± SE, dietary adherence over 12 weeks was 6.0 ± 0.2 and 8.2 ± 0.1, for the low and high adherence groups, respectively. Range of dietary adherence scores were 2.9-7.7 and 7.1-9.9 respectively. For physical activity adherence, mean scores were 5.9 ± 0.2 and 8.5 ± 0.2 for the low and high adherence groups, and ranged from 3.0-7.2 and 7.0-10.0, respectively.
Compared to participants with low self-rated adherence to dietary prescriptions, those with high adherence lost significantly more VAT (22.9 ± 3.7 cm2 vs. 11.7 ± 3.9 cm2 [95% CI, -22.1 to -0.3]) and weight at Week 12 (5.4 ± 0.8 kg vs. 3.5 ± 0.6 kg [95% CI, -3.8 to -0.0]) (Table 2). For physical activity, compared to participants with low adherence, those with high adherence lost significantly more VAT (22.3 ± 3.7 cm2 vs. 11.6 ± 3.6 cm2 [95% CI, -20.7 to -0.8]) (Table 3). Weight loss was also greater for those with high vs. low adherence to physical activity prescriptions (5.0 ± 0.7 kg vs. 3.7 ± 0.7 kg); however, these differences were not significant (95% CI, -3.2 to 0.6). Within study arm comparisons, high dietary adherence and high physical activity adherence had greater VAT and weight loss than their counterpart low adherence groups, but these differences were not significant (Tables 2 and 3). Repeating analyses using % change in VAT and weight instead of absolute change produced similar results. The association between continuous values for self-rated adherence and % change in VAT and weight were also examined. Results were similar to the primary analyses, with the exception of the association between self-rated physical activity adherence and % change in body weight which was found to be significant among all participants (95% CI, 0.0 to 1.3).
TABLE 2. Change in visceral adipose tissue (VAT) and weight by self-rated adherence to dietary prescriptions1
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|
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VAT loss at Wk 12 (cm2)
n=59
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Weight loss at Wk 12 (kg)
n=59
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Self-rated adherence2
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Mean (SE)
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95% CI
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Mean (SE)
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95% CI
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Total
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Low
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11.7 (3.9)
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-22.1 to -0.3
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3.5 (0.6)
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-3.8 to -0.0
|
|
High
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22.9 (3.7)
|
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5.4 (0.8)
|
|
IER+MED3
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Low
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18.5 (6.7)
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-25.0 to 8.4
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4.6 (1.0)
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-4.5 to 0.6
|
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High
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26.8 (4.3)
|
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6.6 (0.9)
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DASH4
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Low
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6.3 (3.9)
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-25.6 to 2.2
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2.6 (0.7)
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-4.0 to 1.1
|
|
High
|
18.0 (6.2)
|
|
4.1 (1.2)
|
|
1Imputed values for missing adherence data. 2Mean self-rated dietary adherence ranging from zero being not at all to ten being following the plan very well, split by median adherence (7.3). 3Intermittent energy restriction combined with a Mediterranean diet. 4Euenergetic Dietary Approaches to Stop Hypertension diet.
TABLE 3. Change in visceral adipose tissue (VAT) and weight by self-rated adherence to physical activity prescriptions1
|
|
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VAT loss at Wk 12 (cm2)
n=59
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Weight loss at Wk 12 (kg)
n=59
|
|
Self-rated adherence2
|
Mean (SE)
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95% CI
|
Mean (SE)
|
95% CI
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Total
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Low
|
11.6 (3.6)
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-20.7 to -0.8
|
3.7 (0.7)
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-3.2 to 0.6
|
|
High
|
22.3 (3.7)
|
|
5.0 (0.7)
|
|
IER+MED3
|
Low
|
17.8 (5.9)
|
-22.8 to 4.8
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5.5 (1.1)
|
-3.0 to 2.5
|
|
High
|
26.8 (4.4)
|
|
5.8 (0.9)
|
|
DASH4
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Low
|
6.8 (4.1)
|
-23.6 to 3.7
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2.5 (0.8)
|
-4.2 to 0.8
|
|
High
|
16.8 (5.8)
|
|
4.2 (1.0)
|
|
1Imputed values for missing adherence data. 2Mean self-rated physical activity adherence ranging from zero being not at all to ten being following the plan very well, split by median adherence (7.1). 3Intermittent energy restriction combined with a Mediterranean diet. 4Euenergetic Dietary Approaches to Stop Hypertension diet.
Participant Feedback
Answering the question, “materials provided were sufficient to be able to follow the diet plan”, 44 (81%) participants rated that they strongly agree or agree, 8 (15%) that they neither agree or disagree, and 2 (4%) participants did not respond. For the question “Would in-house classes or cooking demonstrations have been of interest?” 36 (67%) participants answered yes, 12 (22%) reported no, 2 (4%) were undecided, and 4 (7%) did not answer the question. Women tended to be more interested in the in-house classes or cooking demonstrations than men (75% and 47%, respectively).
The thematic structure identified for the open-ended questions as part of the 6-month post-intervention telephone interview followed the topics of the survey questions including 1) Exercise; 2) Diets; 3) Comments; and 4) Suggestions (29). Participant responses were summarized based on this thematic structure.
Exercise. Almost all (n=46, 96%) participants reported continuing exercise at 6-months post-intervention. Overall, respondents reported 60 types of exercise regimens they adopted or continued after the study, with 31 (65%) reporting “walking” as a primary form of exercise. Other popular exercise included running, swimming, paddling, tennis, golf, cycling, weightlifting, fishing, Zumba, Step Aerobics, Aqua Aerobics, high intensity interval training, calisthenics, stair climbing, and use of a gymnasium.
Diets. Approximately half of the respondents reported “yes”, they were still trying to follow their prescribed diet at 6-months post-intervention (IER+MED, 66.7%; DASH, 44.0%). Of those participants not following the diet at 6-months post-study, many (n=8) reported focusing on a healthy diet without mentioning the specific dietary changes. For example, “Your study increased my awareness regarding foods and I am eating healthier, and use the basics of the study as a guide.” Also, although no longer following their prescribed diet, participants reported substituting nutrient poor items for nutrient dense choices (n=4), reducing their portion size (n=9), decreasing intake of sugar, meat or carbohydrates (n=7), and increasing intake of fruit and vegetables (n=14). An example being, “gave up some snack foods and unhealthy food. More aware of healthier options.” In addition, participants reported adopting a modified version of the study diet with the re-adoption of non-study foods (n=6), for example, “following protocol, but added dark chocolate.”
Comments. Under this theme, praise for the support of the intervention dietitians was the most frequent comment (n=14). For example, “Helpful to have dietitian suggestions and accountability.” Unfamiliarity with the foods prescribed during the study, and preparation of these foods (n=2) was the second most frequent comment.
Suggestions. The most common response, on how to improve the study, was to provide cooking education (n=8) in the form of classes delivered either in-person or online; and the creation of a cookbook to support the study. For example, “would really appreciate cooking classes.” The Identification of more varied foods to support the study was also suggested, including the identification of premade foods (n=3) that would be acceptable for use, and longer study duration (n=1).