The provision of meals for dietary control is a well-established practice in studies investigating physiology and measuring mechanistic outcomes. However, the extent to which meal provision of different compositions at set times influences blood glucose regulation and physical activity patterns, compared to habitual dietary intakes and activity patterns is not known. We aimed to test the hypotheses that the provision of differing food meals would not alter daily activity patterns.
Eight sedentary, overweight/obese men (age: 36±4 y, BMI: 30±2 kg/m2) participated in the randomized crossover study. Participants completed a 7-day habitual recording period followed by 5 days of each dietary intervention (HFD: 15% total energy intake (TEI) carbohydrate, 67% TEI fat and 18% TEI protein vs HCD: 67% TEI carbohydrate, 15% TEI fat and 18% TEI protein). Throughout both the Habitual and Intervention periods energy intake and physical activity patterns (ActiGraph accelerometer) were assessed.
The average 7-day habitual dietary intake was 43±14% TEI carbohydrate, 35±7% TEI fat and 22±9% TEI protein. Across total accelerometer wear time, HFD provision increased sedentary (<100 counts per minute (cpm)) time (P=0.006; +7%, 95%CI:2–11 %) and reduced light (100-1951 cpm) activity time (P=0.01; -6%, 95%CI:-10–2%) compared to the Habitual period. Conversely, the HCD provision tended to reduce sedentary time (P=0.078; -4%, 95%CI:-9–0.5%) and increased light activity time (P=0.03; +5%, 95%CI:1–10%) compared to the Habitual period. No differences in sedentary or light activity time was measured between Habitual periods prior to each diet, nor was there a difference between conditions for moderate-vigorous physical activity at any time.
These preliminary findings indicate that dietary provision (altering habitual macronutrient intake) leads to changes in habitual sedentary and light activity patterns. Therefore, the impact that dietary control has on habitual activity patterns should be considered in investigations where dietary control is required for assessing underlying mechanisms.