Consequence of omitting or adding a meal in man on body composition, food intake, and metabolism

Objective: To investigate in man the consequence on body composition and related biological and metabolic parameters of omitting or adding a meal. Research Methods and Procedures: Twenty-four young normal-weight male subjects were recruited, 12 usual four-meal and 12 usual three-meal eaters, differing only in the consumption of an afternoon meal. They omitted or added a fourth meal during a 28-day habituation period and were asked to report their intake on three 3-day occasions. Before and after this habituation period, subjects participated in a session with a time-blinded procedure, and blood was collected continuously from lunch to the spontaneously requested dinner. Body composition, respiratory quotient, and biochemical parameters were measured in the late evening preceding each session. Results: Omitting a meal was followed by increases in fat mass (360 +/- 115 grams, p < 0.05), late evening leptin concentration (20.7 +/- 11.0%, P < 0.05), and respiratory quotient (3.7 +/- 1.4%, p < 0.05). Increase in the percentage of dietary fat during the habituation period (+4.1 +/- 2.0%, p < 0.05) was correlated with fat mass (r = 0.66, p < 0.05). Adding a meal had no effect, but, in both groups, the change in energy content at this fourth eating occasion was correlated with the change in adiposity. Discussion: Our results suggest that adiposity may increase when young lean male subjects switch from a four- to a three-meal pattern by removing their usual afternoon meal. This effect could be partly mediated by a change in the macronutrient composition of the diet.