Differences in postprandial responses to fat and carbohydrate loads in habitual high and low fat consumers (phenotypes)(Källa.)
J. E. Blundell*, J. Cooling, N. A. King
BioPsychology Group, School of Psychology, University of Leeds, Leeds LS2 9JT, UK
(Received 30 August 2001?Revised 21 February 2002?Accepted 23 March 2002)
The present study investigated metabolic responses to fat and carbohydrate ingestion in lean male individuals consuming an habitual diet high or low in fat. Twelve high-fat phenotypes (HF) and twelve low-fat phenotypes (LF) participated in the study. Energy intake and macronutrient intake variables were assessed using a food frequency questionnaire. Resting (RMR) and postprandial metabolic rate and substrate oxidation (respiratory quotient; RQ) were measured by indirect calorimetry. HF had a significantly higher RMR and higher resting heart rate than LF. These variables remained higher in HF following the macronutrient challenge. In all subjects the carbohydrate load increased metabolic rate and heart rate significantly more than the fat load. Fat oxidation (indicated by a low RQ) was significantly higher in HF than in LF following the fat load; the ability to oxidise a high carbohydrate load did not differ between the groups. Lean male subjects consuming a diet high in fat were associated with increased energy expenditure at rest and a relatively higher fat oxidation in response to a high fat load; these observations may be partly responsible for maintaining energy balance on a high-fat (high-energy) diet. In contrast, a low consumer of fat is associated with relatively lower energy expenditure at rest and lower fat oxidation, which has implications for weight gain if high-fat foods or meals are periodically introduced to the diet.
Mycket intressant! Många intressanta punkter:
- Energiintaget hos högfettsgruppen var 2937 kalorier per dag, d v s 674 kalorier högre än hos högkolhydratsgruppen.
- Högfettsgruppen hade trots högre kaloriintag samma vikt som högkolhydratsgruppen och lika stor mycket kroppsfett - 11 %.
- Högfettsgruppen hade alltså 10 % högre viloenergiförbrukning än högkolhydratsgruppen.
- Fettförbränningen anpassades snabbt och effektivt till fettinnehållet i den fettrika drinken för högfettsgruppen, hos högkolhydratsgruppen var den mycket lägre.
- Kolhydraterna förbrändes lika effektivt hos de båda grupperna.