Are high-fat and low-fat consumers distinct phenotypes? differences in the subjective and behavioural response to energy and nutrient challenges

Abstract

Objective: To characterise the appetite control in habitual high fat (HF) and low fat (LF) phenotypes. Design: Four treatment conditions for each subject group in a fully repeated 2 6 2 6 2 measures design. Setting: The Human Appetite Research Unit at Leeds University, Psychology Department. Subjects: Eight lean HF (mean % fat intake746.7% daily energy) and eight lean LF (mean % fat intake729.9% daily energy) were recruited from the staff/student population of Leeds University. Interventions: All subjects were provided with either a low (2129 kJ) or high (3801 kJ) energy meal at midday and the capacity for compensation was later measured by nutrient challenge (ad libitum consumption of either high fat or high CHO foods). Satiation and satiety were assessed by changes in energy and nutrient intakes, hunger, fullness and food preferences. Results: The energy and nutrient manipulations gave rise to different levels in the rated intensity of hunger between HF and LF (P`0.01). HF rated their baseline hunger at a higher level than LF, and the nutrient induced changes in hunger had a much greater amplitude. HF consumed signi®cantly more energy from the high fat meals than from the high CHO meals (P`0.05); this effect was not observed in LF. HF ate more energy and a greater weight of the high fat foods but less energy and smaller weight of the high CHO foods than did the LF. HF rated the high fat and high CHO foods equally satisfying, tasty and ®lling, whereas LF indicated a preference for high CHO foods (P`0.05). Conclusions: The appetite control in habitual high and low fat consumers is different. HF`passively overconsume' fat whereas this effect is weak in LF. The HF ate a constant weight of food whereas LF ate a more constant level of energy. HF could not distinguish between high and low fat foods suggesting that they were intrinsically insensitive or`taste adapted' whereas LF were fat sensitive. The clear differences disclosed in response to signals generated by the characteristics of ingested food (weight, energy, nutrient composition, taste) suggest that habitual high and low fat consumers can be regarded as distinct behavioural phenotypes. The different styles of appetite control could arise from: (a) intrinsic physiological differences, or (b) a system which is adapted to deal with a particular type of diet. Sponsorship: This study was supported by the Biotechnology and Biological Sciences Research Council (BBSRC).

High and low carbohydrate and fat intakes: limits imposed by appetite and palatability and their implications for energy balance

“…In turn this could disclose information about the variability in appetite control mechanism, which either promote fat intake or limit its consumption. It has already been reported that high and low fat phenotypes display different forms of appetite control (Blundell & Macdiarmid, 1997;Cooling & Blundell, 1998). The implication of the existence of distinct phenotypes Ð with differing behavioural and physiological responses to nutrient challenges Ð is that measures of the`average' responses of Fat carbohydrates and energy density as determinants of total energy intake How does fat affect appetite and energy balance?…”

“…For instance, whether HF or high ED diets promote excess EI. It is perhaps also timely to consider replacing the`traditional' obese-lean dichotomy in describing appetite control and FB with the concept of phenotypes which describe the likely behavioural andaor physiological responses of certain groups of people to dietary factors believed to affect their disposition towards weight gain (Drewnowski, 1995;Cooling & Blundell, 1998). It is also important to consider the generalisability of results found in the laboratory to people living their normal lives in the real world (Blundell & Macdiarmid, 1997).…”

High-fat and low-fat phenotypes: habitual eating of high- and low-fat foods not related to taste preference for fat

“…In a test meal situation HF were more prone to passive overconsumption of fat and demonstrated large fluctuations in hunger in comparison to LF. In contrast LF were sensitive to the fat content in a test meal and did not overconsume (Cooling & Blundell, 1998a). Taken together the eating behaviour of HF carries many risk factors for the development of a positive energy balance, but, at least in young adult males, weight gain does not occur.…”

“…These groups appear to constitute distinct behavioural phenotypes: the high-fat phenotype (HF) and low-fat phenotype (LF). By definition HF consume more fat than LF, but also report more energy intake and less percentage carbohydrate intake (Cooling & Blundell, 1998a). These patterns of nutrient intakes are achieved by HF consuming significantly more dairy products, meat, fish and alcohol, but less cereals, bread, fruit and vegetables than LF (Blundell & Cooling, 1999).…”

High-fat and low-fat (behavioural) phenotypes: biology or environment?

“…When subjected to energy and macronutrient challenges in order to evaluate the responses of the appetite control system, clear differences between the groups were demonstrated. Initially, HF displayed higher initial hunger levels, with a much sharper decline in hunger in response to meals or nutrient loads (Cooling & Blundell, 1998a). After eating, hunger recovered more rapidly in HF compared with LF ( Fig.…”