Background:
Sleep is emerging as an important factor that impacts dietary habits, physical activity, and metabolism. However, minimal attention is typically given to sleep in traditional lifestyle interventions. The purpose of these analyses was to examine baseline associations between sleep and physical activity and perceived barriers to healthy eating, which are two common lifestyle intervention targets, in a sample of apparently healthy adults enrolled in a behavioral weight loss intervention study.
Methods:
150 overweight adults (51.1±10.2 y; 91% female; 79% Caucasian) participated in a 12-month lifestyle intervention that featured adaptive ecological momentary assessment. Sleep, physical activity, barriers to healthy eating and body habitus/composition were assessed prior to the intervention. Objective sleep was estimated with 7 days of wrist-worn actigraphy (Philips Actiwatch 2); sleep onset latency (SOL; the amount of time it takes to fall asleep after going to bed), sleep efficiency (SE; the percentage of time in bed that is spent asleep), and total sleep time (TST; total time spent asleep) served as the primary actigraphic sleep variables. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Physical activity was assessed with 7 days of waist-worn accelerometry (ActiGraph GT3x). Perceived barriers to healthy eating were assessed with the Barriers to Healthy Eating questionnaire. Body mass index (BMI) served as the measure of body habitus, and body fat was assessed with bioelectrical impedance.
Results:
Mean BMI and body fat for the sample were 34.0±4.6 kg/m2 and 43.7±5.5%, respectively. Mean TST was 6.6±0.8 h/night; approximately 23% of the sample averaged less than 6 hours of sleep. Mean SOL and SE for the sample were 15.3±16.2 min and 85.7±6.1%, respectively. Based on the PSQI, 52.0% of the sample had poor sleep quality. Following adjustment for age, sex, and race, longer SOL was associated with fewer steps/day (β=-.19, p=.02) and less time spent in moderate to vigorous physical activity (MVPA; β=-.16, p=.03), and lower SE was related to less MVPA (β=.15, p=.04). Shorter TST was associated with greater barriers to healthy eating (β=-.16, p=.05). Longer SOL was associated with higher BMI (β=.16, p=.05) and body fat % (β=.15, p=.03), and lower SE was related to higher body fat % (β=-.13, p=.06).
Conclusions:
Short sleep duration and sleep disturbance were highly prevalent in this sample of overweight adults. Significant associations were observed between sleep and measures of body habitus/composition and eating and physical activity habits. Efforts to improve sleep during a behavioral intervention for weight loss may reduce barriers to healthy eating and improve physical activity habits as well as weight loss outcomes.
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