Restrained Eating Behavior and the Metabolic Response to Dietary Energy Restriction in Women

Abstract

KEIM, NANCY L., AND WILLIAM F. HORN. Restrained eating behavior and the metabolic response to dietary energy restriction in women. Obes Res. 2004;12:141-149. Objective: To determine whether prior eating behavior characterized by dietary restraint alters responses in energy expenditure and substrate oxidation associated with a shortterm, energy-restricted diet. Research Methods and Procedures:A repeated-measures, 3-day diet-intervention study of adequate (125 kJ/kg of body weight) or restricted (62.5 kJ/kg) energy intake was conducted with 30 women, 20 to 46 years, BMI 25 to 45 kg/m 2 , whose prior eating behavior was "restrained" or "unrestrained." The Eating Inventory (cognitive restraint subscale) was used to measure restrained eating behavior. Energy expenditure and substrate oxidation were measured after a 12-hour fast and during the first and fourth hours after a standard meal. Plasma glucose, nonesterified fatty acids, and insulin were measured at corresponding times. Body composition was determined by total body electrical conductivity. Results: Resting energy expenditure was not affected by 3 days of energy restriction. Short-term energy restriction resulted in lower respiratory-exchange ratios, higher rates of fat oxidation, and lower rates of carbohydrate oxidation. Subjects classified as restrained eaters had higher postprandial respiratory-exchange ratios and carbohydrate-oxidation rates compared with unrestrained eaters. Fasting insulin concentrations were lower in restrained eaters. These effects associated with prior eating behavior were independent of the diet intervention.Discussion: Metabolic outcomes associated with a 3-day energy-restricted diet (i.e., increased fat oxidation and decreased carbohydrate oxidation) were not affected by prior restrained eating behavior. However, restrained eating behavior was associated with increased carbohydrate oxidation after a mixed meal. This effect of restrained eating behavior may be attributable to increased insulin sensitivity.

Effects of exercise and restrained eating behaviour on appetite control

“…Lower fasting insulin levels have previously been reported in restrained women (112,113) , as well as lower insulin resistance (based on the HOMA model) (112) . However, body weight was found to be a confounder in the latter study (112) , which showed increased fasting insulin sensitivity in restrained eaters.…”

“…Another study, however, has shown no significant differences in insulin, glucagon or PP cephalic-phase responses to the sham-feeding of a high-fat or low-fat cake between restrained and unrestrained individuals (119) . Increased levels of fasting TAG (109) and NEFA (83) and lower fasting insulin (112,113) and leptin levels, even after controlling for fat mass (120)(121)(122) , have also been reported in restrained eaters. Moreover, higher levels of cortisol, indicative of increased psychological stress, probably in association with 'eating behaviour', has also been found in some (123,124) but not all studies (111) .…”

“…Moreover, in a free-living environment restrained eaters have been shown to consume less energy (109) (although that may be the result of underreporting (110) ), take fewer meals and exhibit a higher preference for low-energy and healthy food (109) , including fruits and vegetables (111) , compared with unrestrained eaters. Interestingly, a link has been suggested between restrained eating behaviour and altered physiological pathways; restrained eating has been shown to impact on metabolic (83,109) as well as endocrine (112)(113)(114) functions. A lower total EE has been described in restrained eaters (115) , but it does not seem to be driven by a lower BMR (116) .…”

“…The metabolic response to a meal seems also to be affected by the level of restraint. Restrained women have been shown to have a reduced diet-induced thermogenesis (125) and an increased carbohydrate oxidation after a mixed meal (112) , as well as a reduced secretion of noradrenaline following a test meal (113) . It has been proposed that this change in fuel oxidation may be related to an increased insulin sensitivity in restrained individuals (112) .…”

“…Restrained women have been shown to have a reduced diet-induced thermogenesis (125) and an increased carbohydrate oxidation after a mixed meal (112) , as well as a reduced secretion of noradrenaline following a test meal (113) . It has been proposed that this change in fuel oxidation may be related to an increased insulin sensitivity in restrained individuals (112) . Another study, however, has found that high disinhibition rather than high restraint is associated with a lower thermic effect of food (116) .…”