Background: Certain individuals appear to be resistant to weight gain in an obesigenic environment, yet the mechanisms for this adaptation are unclear. These individuals may sense positive energy balance more appropriately than those individuals prone to weight gain.
Research methods and procedures: Thirteen thin (7 women, 6 men) and 9 reduced-obese (5 women, 4 men) individuals were studied. Measures of intake were obtained using visual analog scales before and after each meal during eucaloric feeding and during three days of 50% overfeeding. Ad libitum energy intake was measured post-overfeeding.
Results: Overfeeding resulted in a significant reduction in pre-meal hunger in the thin (68+/-6 to 41+/-6 mm, p<0.0001) compared to the reduced-obese individuals (63+/-7 to 65+/-7 mm, p=0.67). There was a significantly greater increase (p=0.0016) in post-meal satiety scores during overfeeding in the thin (65+/-4 to 88+/-4 mm, p<0.0001) compared to the reduced-obese individuals (72+/-5 to 80+/-5 mm, p=0.04). Thin women had a 30% reduction in daily energy intake (1831+/-47 to 1273+/-79 kcal/day, p=0.005) after overfeeding while no difference was seen in the thin men or reduced-obese group.
Discussion: Thin individuals appear to sense positive energy balance more appropriately with changes in measures of intake than reduced-obese individuals. These findings are especially true in thin women.