Covert manipulation of the dietary fat to carbohydrate ratio of isoenergetically dense diets: effect on food intake in feeding men ad libitum.
OBJECTIVE
High-fat, high energy-density (HF, HED) diets promote an increase in energy intakes relative to low-fat lower-energy density diets (LF, LED). This study examined whether HF diets promote higher levels of energy intake when isoenergetically dense (IE) relative to LF (high carbohydrate) diets, as predicted by glucostatic and glycogenostatic models for energy intake regulation.


METHODS
Six normal-weight healthy men [mean age (SD) = 37.33 (13.32 y) mean weight = 73.03 (5.14 kg), mean height = 1.80 (0.05 m)].


METHODS
Six men were each studied three times (factorial design) during 14-d throughout which they had ad libitum access to one of three covertly-manipulated diets. The fat, carbohydrate (CHO) and protein in each diet (as % energy) were 20:68:12, [low-fat (LF)]; 40:48:12, [medium-fat (MF)]; 60:28:12 [high-fat (HF)], with 2-d maintenance (1.4 x BMR, MF) beforehand. Within each diet every item was of the same composition and offered as a 3-d rotating menu.


METHODS
Energy and nutrient intakes, body weight, subjective pleasantness and satisfaction of the food.


RESULTS
Energy intakes were 10.69, 11.02 and 10.90 MJ/d on the LF, MF and HF diets respectively. The increase in energy intake that occurred in previous studies when the energy density of the diet was increased by addition of fat was not apparent when LF, MF and HF diets were of the same energy density.


CONCLUSIONS
Neither carbohydrate nor fat intake were tightly regulated. These data do not support an entirely glucostatic or glucogenostatic model of food intake regulation.
Stubbs
R J
RJ
MRC Dunn Clinical Nutrition Centre, Cambridge, UK. J Stubbs@rri.sari.ac.uk
Harbron
C G
CG
Prentice
A M
AM
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating; D002149:Energy Intake; D005502:Food; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D013649:Taste
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins