THE ROLE OF MACRONUTRIENT SELECTION IN DETERMINING PATTERNS OF FOOD-INTAKE IN OBESE AND NONOBESE WOMEN

Objective: Examination of the role of macronutrient selection in deter mining patterns of food intake in obese and non-obese women. Design: I nventory: food intake diaries of two weekdays and one weekendday; Expe riment randomized. Setting: Inventory: in daily life. Experiment: depa rtment of Human Biology, University of Limburg. Subjects: 68 subjects: 34 obese and 34 non-obese, age 20-50 years, selected based on accurat e completion of food intake diaries (<10% underreporting); a sub-sampl e of 32 (16 obese and 16 nonobese) was assigned to the experiment. Int erventions: An ample choice of food items consisting of mainly one mac ronutrient each were offered 4 and 6 times per day, with different mac ronutrient compositions per day, ranging from 1-77 en% fat, 3-45 en% p rotein, and 19-96 en% carbohydrate. Results: Selection, namely food ch oice that differs from random consumption, took place at breakfast in favour of carbohydrate, and at dinner in favour of fat. Habituation, n amely a decreased response on the same stimulus, occurred after the fo urth exposure to a single macronutrient buffet. For protein this was e xpressed as a significantly increased satiety score per kJ ingested; f or fat as a significant drop in hedonic value; for carbohydrate as a s ignificantly increased desire for a different taste, all (P<0.05). Com pensation, ie a correction afterwards for an earlier unusual macronutr ient composition, resulting in a close to usual macronutrient composit ion of 24 h food intake, occurred at dinner, for a previous unusually low fat and high carbohydrate intake. Conclusions: A pattern of macron utrient intake was achieved by selection and compensation. Habituation occurred at the fourth exposure of a single macronutrient. Descriptor s: Macronutrient intake pattern, composition, habituation, specific sa tiety, macronutrient selection, macronutrient intake compensation, hum ans.