Background: 4-day of 70% energy-restriction enhances gastrointestinal sensitivity to nutrients, associated with an enhanced energy intake-suppressant effect of nutrients, including lipid. Whether these changes occur with 30% energy-restriction and are sustained in the longer-term is unknown.
Objective: We hypothesized that: i) in lean and obese men, 4-day of 30% energy-restriction would enhance the effects of intraduodenal lipid on gastrointestinal motility, gut hormones, appetite/energy intake, and ii) in the obese men, 12-week energy-restriction associated with weight-loss would diminish the effects of acute energy-restriction in responses to lipid.
Design: 12 obese males were studied before starting the diet (“baseline”), and 4 days (“day-5”), 4 weeks (“week-4”) and 12 weeks (“week-12”) on a 30% energy-restricted diet, while 12 lean males were studied at baseline, and 4 days on a 30% energy-restricted diet; each time antropylorododenal pressures, gut hormones and appetite were measured during a 120-min (2.86 kcal/min) intraduodenal lipid infusion and energy intake at a buffet-lunch.
Results: On day-5, fasting cholecystokinin decreased, and ghrelin increased, in lean (P<0.05), but not obese men, and lipid-stimulated cholecystokinin and peptide-YY and desire-to-eat were greater in both groups (P<0.05), with no difference in energy intake, compared with baseline. In obese men, 12-week energy-restriction led to weight-loss (9.7±0.7 kg). Lipid-induced basal pyloric pressures (BPP), peptide-YY and desire-to-eat were greater (P<0.05), while amount eaten was less (P<0.05), at week-4 and week-12 compared with baseline.
Conclusions: 4-day of 30% energy-restriction modestly affects the responses to intraduodenal lipid in health and obesity, but not energy intake, while 12-week of energy-restriction, associated with weight-loss, enhances lipid-induced BPP and peptide-YY, and reduces food intake (despite increased desire-to-eat), suggesting that energy-restriction increases gastrointestinal “sensitivity” to lipid.