Effects of acute dietary restriction on gut motor, hormone and energy intake responses to duodenal fat in obese men.
BACKGROUND
Previous patterns of energy intake influence gastrointestinal function and appetite, probably reflecting changes in small-intestinal nutrient-mediated feedback. Obese individuals consume more fat and may be less sensitive to its gastrointestinal and appetite-suppressant effects than lean individuals.


OBJECTIVE
To evaluate the hypothesis that, in obese individuals, the effects of duodenal fat on gastrointestinal motor and hormone function, and appetite would be enhanced by a short period on a very-low-calorie diet (VLCD).


METHODS
Eight obese men (body mass index 34±0.6  kg  m(-2)) were studied on two occasions, before (V1), and immediately after (V2), a 4-day VLCD. On both occasions, antropyloroduodenal motility, plasma cholecystokinin (CCK), peptide-YY (PYY) and ghrelin concentrations, and appetite perceptions were measured during a 120-min intraduodenal fat infusion (2.86  kcal  min(-1)). Immediately afterwards, energy intake was quantified.


RESULTS
During V2, basal pyloric pressure and the number and amplitude of isolated pyloric pressure waves (PWs) were greater, whereas the number of antral and duodenal PWs was less, compared with V1 (all P<0.05). Moreover, during V2, baseline ghrelin concentration was higher; the stimulation of PYY and suppression of ghrelin by lipid were greater, with no difference in CCK concentration; and hunger and energy intake (kJ; V1: 4378±691, V2: 3634±700) were less (all P<0.05), compared with V1.


CONCLUSIONS
In obese males, the effects of small-intestinal lipid on gastrointestinal motility and some hormone responses and appetite are enhanced after a 4-day VLCD.
Brennan
I M
IM
University of Adelaide Discipline of Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
Seimon
R V
RV
Luscombe-Marsh
N D
ND
Otto
B
B
Horowitz
M
M
Feinle-Bisset
C
C
D001069:Appetite Regulation / Q000502:physiology; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D031204:Caloric Restriction; D004386:Duodenum / Q000503:physiopathology*; D002149:Energy Intake / Q000502:physiology*; D005215:Fasting / Q000502:physiology; D005768:Gastrointestinal Hormones / Q000097:blood; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000503:physiopathology*
D015415:Biomarkers; D005768:Gastrointestinal Hormones