Subjective Measures Of Appetite Research Articles

Acute Effect of Oatmeal on Subjective Measures of Appetite and Satiety Compared to a Ready-to-Eat Breakfast Cereal: A Randomized Crossover Trial

Objective: The physicochemical properties of soluble oat fiber (β-glucan) affect viscosity-dependent mechanisms that influence satiety. The objective of this study was to compare the satiety impact of oatmeal with the most widely sold ready-to-eat breakfast cereal (RTEC) when either was consumed as a breakfast meal. Methods: Forty-eight healthy individuals ≥18 years of age were enrolled in a randomized crossover trial. Following an overnight fast, subjects consumed either oatmeal or RTEC in random order at least a week apart. The breakfasts were isocaloric and contained 363 kcal (250 kcal cereal, 113 kcal milk). Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. The content and physicochemical properties of oat β-glucan were determined. Appetite and satiety responses were analyzed by area under the curve (AUC). Physicochemical properties were analyzed using t tests. Results: Oatmeal, higher in fiber and protein but lower in sugar than the RTEC, resulted in greater increase in fullness (AUC: p = 0.005 [120 minute: p = 0.0408, 180 minute: p = 0.0061, 240 minute: p = 0.0102]) and greater reduction in hunger (AUC: p = 0.0009 [120 minute: p = 0.0197, 180 minute: p = 0.0003, 240 minute: p = 0.0036]), desire to eat (AUC: p = 0.0002 [120 minute: p = 0.0168, 180 minute: p < 0.0001, 240 minute: p = 0.0022]), and prospective intake (AUC: p = 0.0012 [120 minute: p = 0.0058, 180 minute: p = 0.006, 240 minute: p = 0.0047]) compared to the RTEC. Oatmeal had higher β-glucan content, higher molecular weight (p < 0.0001), higher viscosity (p = 0.025), and larger hydration spheres (p = 0.0012) than the RTEC. Conclusion: Oatmeal improves appetite control and increases satiety. The effects may be attributed to the viscosity and hydration properties of its β-glucan content.

Changes in mechanisms proposed to mediate fat loss following an acute bout of high-intensity interval and endurance exercise

The purpose of this study was to investigate the acute effects of endurance exercise (END; 65% V̇O2peak for 60 min) and high-intensity interval exercise (HIE; four 30 s Wingates separated by 4.5 min of active rest) on cardiorespiratory, hormonal, and subjective appetite measures that may account for the previously reported superior fat loss with low volume HIE compared with END. Recreationally active males (n = 18) completed END, HIE, and control (CON) protocols. On each test day, cardiorespiratory measures including oxygen uptake (V̇O2), respiratory exchange ratio (RER), and heart rate were recorded and blood samples were obtained at baseline (BSL), 60 min after exercise, and 180 min after exercise (equivalent times for CON). Subjective measures of appetite (hunger, fullness, nausea, and prospective consumption) were assessed using visual analogue scales, administered at BSL, 0, 60, 120, and 180 min after exercise. No significant differences in excess postexercise oxygen consumption (EPOC) were observed between conditions. RER was significantly (P < 0.05) depressed in HIE compared with CON at 60 min after exercise, yet estimates of total fat oxidation over CON were not different between HIE and END. No differences in plasma adiponectin concentrations between protocols or time points were present. Epinephrine and norepinephrine were significantly (P < 0.05) elevated immediately after exercise in HIE compared with CON. Several subjective measures of appetite were significantly (P < 0.05) depressed immediately following HIE. Our data indicate that increases in EPOC or fat oxidation following HIE appear unlikely to contribute to the reported superior fat loss compared with END.

Long-Term Persistence of Hormonal Adaptations to Weight Loss

Most obese people can achieve short-term weight loss through dietary restriction, but only a small minority can maintain the reduced weight loss in the long-term. Failure to maintain the initial weight loss may be associated with acute compensatory changes in the circulating levels of several peripheral appetite-regulating hormones that occur as a physiologic response to caloric restriction. It is not known whether these changes are transient or are sustained over time. The present study investigated changes in blood levels of these hormones during 12 months in 50 overweight or obese patients without diabetes who had been on a very low energy diet in a 10-week weight-loss program. At baseline (week 0), week 10, and week 62, circulating levels of hormonal regulators of appetite and subjective ratings of appetite were examined. The hormones investigated included leptin, ghrelin, peptide YY, amylin, cholecystokinin, gastric inhibitory polypeptide, glucagon-like peptide 1, pancreatic polypeptide, and insulin. Weight loss at 10 weeks (mean [± SE], 13.5 ± 0.5 kg) was associated with significant reductions in levels of leptin, peptide YY, cholecystokinin, insulin (P < 0.001 for all), and amylin (P = 0.002) and increased levels of ghrelin (P < 0.001), gastric inhibitory polypeptide (P = 0.004), and pancreatic polypeptide (P = 0.008). A significant increase occurred in subjective measures of appetite, including hunger and the desire to eat (P < 0.001). At 62 weeks, circulating levels of these hormones did not revert to baseline levels recorded before weight loss. Significant differences from baseline persisted in levels of leptin (P < 0.001), peptide YY (P < 0.001), cholecystokinin (P = 0.04), insulin (P = 0.01), ghrelin (P < 0.001), gastric inhibitory polypeptide (P < 0.001), and pancreatic polypeptide (P = 0.002), as well as subjective measures of appetite (P < 0.001). These findings indicate that the high rate of relapse in obese people after initial weight loss through dieting has a strong physiological basis. Successful long-term management of obesity will require the development of treatment strategies to counteract the persisting compensatory changes in circulatory levels of appetite-regulating hormones that encourage weight regain.

Acute ingestion of resistant starch reduces food intake in healthy adults

Resistant starch (RS), a non-viscous dietary fibre, may have postprandial effects on appetite regulation and metabolism, although the exact effects and mechanisms are unknown. An acute randomised, single-blind crossover study, aimed to determine the effects of consumption of 48 g RS on appetite compared to energy and available carbohydrate-matched placebo. Twenty young healthy adult males consumed either 48 g RS or the placebo divided equally between two mixed meals on two separate occasions. Effects on appetite were assessed, using an ad libitum test meal and 24-h diet diaries for energy intake, and using visual analogue scales for subjective measures. Changes to postprandial glucose, insulin and C-peptide were also assessed. There was a significantly lower energy intake following the RS supplement compared to the placebo supplement at both the ad libitum test meal (5241 (sem 313) v. 5606 (sem 345) kJ, P = 0.033) and over the 24 h (12 603 (sem 519) v. 13 949 (sem 755) kJ, P = 0.044). However, there was no associated effect on subjective appetite measures. Postprandial plasma glucose concentrations were not significantly different between supplements, but there was a significantly lower postprandial insulin response following the RS supplement (P = 0.029). The corresponding C-peptide concentrations were not significantly different, although the ratio of C-peptide to insulin was higher following the RS supplement compared to placebo (P = 0.059). These results suggest that consumption of 48 g RS, over a 24-h period, may be useful in the management of the metabolic syndrome and appetite. Further studies are required to determine the exact mechanisms.

Enrichment of yoghurt with protein and fiber reduces appetite.

The objective of this study was to confirm that protein and fiber enrichment in a dairy matrix is a way to reduce appetite. We tested the effects of yoghurts differing in the amount of protein (fixed fiber) on subjective sensations of appetite, hormonal parameters and subsequent food intake. The study was designed as a randomized, cross-over (4 periods), double-blind study. Twenty healthy females (age 25±7 yr, BMI of 24.5±1.4 kg/m 2 ), not dietary restrained, completed the study. An iso-volume (400 g) and iso-energetic (∼360 kcal) load was consumed as breakfast. Four yoghurts were tested, consisting of a control (4% protein, no fibre), 2 medium protein (MP) (∼7% protein, 0.5% fiber) and a high protein (HP) (12.9% protein, 0.5% fiber) product. Subjective measures of appetite (including hunger, fullness) were assessed and blood samples (including CCK, GLP-1 and ghrelin) were drawn regularly in the 4 h following the consumption of yoghurts. Subsequent food intake was measured at lunch and dinner. Over the 4 h following breakfast, HP-induced lower hunger feeling compared with the control ( p <0.05), higher CCK and lower ghrelin ( p <0.05) levels compared with the control or MP products. At high doses of protein (12.9%), the hunger profile was in line with biological markers involved in hunger/satiety (CCK and Ghrelin). There was no effect on ad libitum food consumption over the day. These results suggest that at high doses and particular conditions (400 g of yoghurt at breakfast), enrichment in protein and fibre reduces appetite via subjective sensations and hormonal responses.

Effects of exercise on gut peptides, energy intake and appetite

This study investigated the acute effects of exercise on the postprandial levels of appetite-related hormones and metabolites, energy intake (EI) and subjective measures of appetite. Ghrelin, polypeptide YY (PYY), glucagon-like peptide-1 (GLP-1) and pancreatic polypeptide (PP) were measured in the fasting state and postprandially in 12 healthy, normal-weight volunteers (six males and six females) using a randomised crossover design. One hour after a standardised breakfast, subjects either cycled for 60 min at 65% of their maximal heart rate or rested. Subjective appetite was assessed throughout the study using visual analogue scales and subsequent EI at a buffet meal was measured at the end (3-h post-breakfast and 1-h post-exercise). Exercise significantly increased mean PYY, GLP-1 and PP levels, and this effect was maintained during the post-exercise period for GLP-1 and PP. No significant effect of exercise was observed on postprandial levels of ghrelin. During the exercise period, hunger scores were significantly decreased; however, this effect disappeared in the post-exercise period. Exercise significantly increased subsequent absolute EI, but produced a significant decrease in relative EI after accounting for the energy expended during exercise. Hunger scores and PYY, GLP-1 and PP levels showed an inverse temporal pattern during the 1-h exercise/control intervention. In conclusion, acute exercise, of moderate intensity, temporarily decreased hunger sensations and was able to produce a short-term negative energy balance. This impact on appetite and subsequent energy homeostasis was not explained by changes in postprandial levels of ghrelin; however, 'exercise-induced anorexia' may potentially be linked to increased PYY, GLP-1 and PP levels.

Ghrelin response to carbohydrate-enriched breakfast is related to insulin1–3

Ghrelin plays an important role in the regulation of food intake. Little is known about how ghrelin concentrations are modified by dietary factors. We examined the effects of both amount and type of carbohydrate on ghrelin concentrations and all correlations among the variables ghrelin, glucose, insulin, leptin, and all 4 subjective measures of appetite. Twenty healthy nonobese men were studied in a double-blind, randomized, crossover design. Subjective measures of appetite and concentrations of ghrelin, glucose, insulin, and leptin were frequently assessed for 4 h after liquid breakfast meals differing in energy content and carbohydrate structure-ie, water, low-calorie (LC) meal, high-calorie simple carbohydrate (HC-SC) meal, and high-calorie complex carbohydrate (HC-CC) meal. Ghrelin concentrations decreased after the HC-SC breakfast by 41%, after the HC-CC breakfast by 33%, and after the LC breakfast by 24%. No significant differences in ghrelin concentration among the 3 breakfasts were observed until 120 min. Ghrelin concentrations were correlated with subjective measures of hunger (r=0.51) and fullness (r=-0.44). The percentage decrease in ghrelin between 0 and 30 min was inversely correlated with the percentage increases in insulin (r=-0.76) and glucose (r=-0.79) but not with changes in leptin (r=0.10). The percentage changes in ghrelin concentrations between 30 and 180 min were correlated with the percentage changes in insulin (r=-0.53) and leptin (r=-0.47) but not with changes in glucose (r=0.22). The results support the hypothesis that ghrelin requires postgastric feedback, which may be regulated through insulin.

A meta-analysis of the effect of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake in humans.

Seven studies have now been published pertaining to the acute effect of iv administration of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake. In four of these studies energy intake was significantly reduced following the glucagon-like peptide-1 infusion compared with saline. In the remaining studies, no significant effect of glucagon-like peptide-1 could be shown. Lack of statistical power or low glucagon-like peptide-1 infusion rate may explain these conflicting results. Our aim was to examine the effect of glucagon-like peptide-1 on subsequent energy intake using a data set composed of subject data from previous studies and from two as yet unpublished studies. Secondly, we investigated whether the effect on energy intake is dose dependent and differs between lean and overweight subjects. Raw subject data on body mass index and ad libitum energy intake were collected into a common data set (n = 115), together with study characteristics such as infusion rate, duration of infusion, etc. From four studies with comparable protocol the following subject data were included if available: plasma concentrations of glucagon-like peptide-1, subjective appetite measures, well-being, and gastric emptying rate of a meal served at the start of the glucagon-like peptide-1 infusion. Energy intake was reduced by 727 kJ (95% confidence interval, 548-908 kJ) or 11.7% during glucagon-like peptide-1 infusion. Although the absolute reduction in energy intake was higher in lean (863 kJ) (634-1091 kJ) compared with overweight subjects (487 kJ) (209-764 kJ) (P = 0.05), the relative reduction did not differ between the two groups (13.2% and 9.3%, respectively). Stepwise regression analysis showed that the glucagon-like peptide-1 infusion rate was the only independent predictor of the reduction in energy intake during glucagon-like peptide-1 (7-36) amide infusion (r = 0.4, P < 0.001). Differences in mean plasma glucagon-like peptide-1 concentration on the glucagon-like peptide-1 and placebo day (n = 43) were related to differences in feelings of prospective consumption (r = 0.40, P < 0.01), fullness (r = 0.38, P < 0.05), and hunger (r = 0.26, P = 0.09), but not to differences in ad libitum energy intake. Gastric emptying rate was significantly lower during glucagon-like peptide-1 infusion compared with saline. Finally, well-being was not influenced by the glucagon-like peptide-1 infusion. Glucagon-like peptide-1 infusion reduces energy intake dose dependently in both lean and overweight subjects. A reduced gastric emptying rate may contribute to the increased satiety induced by glucagon-like peptide-1.

Soft drinks with aspartame: Effect on subjective hunger, food selection, and food intake of young adult males

Ingestion of aspartame-sweetened beverages has been reported to increase subjective measures of appetite. This study examined the effects of familiar carbonated soft drinks sweetened with aspartame on subjective hunger, energy intake and macronutrient selection at a lunch-time meal. Subjects were 20 normal weight young adult males, classified as either restrained or nonrestrained eaters. Four treatments of carbonated beverages included 280 ml of mineral water, one can of a soft drink (280 ml) consumed in either 2 or 10 minutes, or two cans of a soft drink (560 ml) consumed in 10 minutes, administered at 11:00 a.m. Subjective hunger and food appeal were measured from 9:30 a.m. to 12:30 p.m., and food intake data were obtained from a buffet lunch given at 12:00 noon. There were no treatment effects on energy intake, macronutrient selection or food choice at the lunch-time meal, or food appeal, though restrained eaters consumed more than nonrestrained eaters in all four treatment conditions. Consumption of two soft drinks (560 ml, 320 mg aspartame) significantly reduced subjective hunger from 11:05 a.m. to 11:30 a.m. compared to one soft drink (280 ml, 160 mg aspartame) or 280 ml of mineral water. Thus ingestion of soft drinks containing aspartame did not increase short-term subjective hunger or food intake.