Rationale and protocol for time-based energy intake goals within an obesity care lifestyle intervention: Daily eating...

This publication outlines the rationale and protocol for the Daily Eating Patterns for Total Health (DEPTH) trial, detailing its motivation, aims, design, intervention, and measures. This randomized clinical trial examines how time-based energy goals applied within a 12-month obesity care lifestyle intervention influences percent weight loss, dietary temporal patterns, sleep regularity, and appetite regulation. One hundred seventy-four adults (ages: 25-60 y; BMI: 27-45 kg/m²) will be randomized to one of three interventions: DEPTH-Morning, DEPTH-Evening, or DEPTH. All participants will receive 33 sessions of an obesity care lifestyle intervention that includes five separate dietary goals: (1) 1200-1500 kcal/day, (2) ≤ 30% energy from fat, (3) a 12-h eating window, (4) first eating occasion within 60 min of awakening, and (5) 3 meals and 1 snack per day. They will also aim for 200 min/wk. of moderate- to vigorous-intensity physical activity. DEPTH-Morning participants will be given the goals to consume 70% of energy in two meals and one snack during the first six hours of the 12-h eating window, and 30% of energy in one meal in the last six hours of the eating window (morning-loaded distribution). DEPTH-Evening will be given goals to adopt the opposite pattern (afternoon/evening-loaded distribution). DEPTH participants will have no specific time-based energy intake goals. Measures of anthropometrics, dietary intake, sleep, and appetite regulation will be assessed at 0, 3, 6, and 12-months. This study will provide insights into the role of time-based energy intake goals, a form of chrononutrition, on obesity care outcomes.