Hidden fat facilitates passive overconsumption.

Food intake regulation may be disturbed when sensory signals from foods are disconnected from their metabolic properties. Consumption of high-fat, energy-dense foods may stimulate passive overconsumption, because these foods do not provide sensory signals in accordance with the actual nutrient content. We examined the effects of perception of fat on energy intake in adults after overfeeding (Study 1) and on energy intake during a meal (Study 2). In study 1, 57 participants consumed 6 mandatory lunches differing in energy level (100, 200, and 300% of a standard lunch intake) and fat condition (visible fat and hidden fat). Ad libitum energy intake was measured during subsequent meals. In Study 2, 51 participants consumed 2 lunches that were high in visible or hidden fats. We measured ad libitum energy intake during lunch. In Study 1, the energy intake at dinner was 8% higher in the hidden fat condition than in the visible fat condition (P = 0.0046). A main effect was also found for the energy level of the lunch (P < 0.0001), with the highest intake following the 100% energy level and the lowest intake following the 300% energy level. In Study 2, the energy intake was 9% higher in the hidden fat condition than in the visible fat condition (P = 0.013). Perception of fat influences energy intake. In the presence of visible fats, energy intake was lower than in the presence of hidden fats, suggesting that hidden fats may contribute to overconsumption. Appropriate sensory signals may be important in preventing overconsumption.