Short-term Energy Intake Research Articles

Effect of exercise time of day on energy intake in normal weight males

Introduction: Although the manipulation of exercise and dietary intake to achieve successful weight loss has been extensively studied, the effect of exercise itself on energy intake is not well understood. The purpose of this study was to investigate the effect of the time of day that exercise is performed (morning compared to afternoon) on short-term energy intake. Methodology: Nine healthy male participants completed three trials; morning exercise, afternoon exercise and control (no exercise) in a random crossover design.

The level of carbonation of a sugar-sweetened beverage preload affects satiety and short-term energy and food intakes

The consumption of sugar-sweetened beverages is associated with increased incidence of overweight and obesity, and a factor underlying this putative link could be the relatively low levels of satiety that may be induced by these beverages. Although many sugar-sweetened beverages are carbonated, little attention has been given to the potential effects of level of carbonation on satiety and subsequent intakes. We hypothesized that increasing the level of carbonation in a sugar-sweetened beverage would increase satiety and decrease intakes in the short term. Using a randomized, within-subject cross-over design, thirty non-obese subjects (fifteen women, fifteen men) participated on three occasions, 1 week apart. Following a standard breakfast, subjects consumed a beverage preload 10 min before consuming a lunch ad libitum. Preloads were the same sugar-sweetened beverage (400 ml, 639 kJ) with three levels of carbonation, which were low (1.7 volumes), medium (2.5 volumes) and high (3.7 volumes). Satiety was assessed using visual analogue scales and intakes were measured at the lunch and for the rest of the day. Compared with the beverage with low carbonation, consumption of the beverages with medium and high carbonation led to significantly (P < 0.05) higher satiety until lunch, when intakes of food and energy were significantly (P < 0.05) lower. There were no significant effects on satiety following lunch or on intakes for the rest of the day. This short-term study suggests that the level of carbonation may need to be taken into account when assessing potential effects of beverages on satiety and intake.

A comparison of short-term appetite and energy intakes in normal weight and obese boys following glucose and whey-protein drinks

To compare the effect of glucose and whey-protein preloads on satiety and food intake (FI) as affected by time to the next meal and body composition in normal weight (NW) and obese (OB) boys. Cross-sectional clinical intervention study of the effect of caloric preloads on FI control in boys. Seventeen NW (body mass index (BMI)=18.9+/-0.5 kg/m(2); age=12.2+/-0.3 years) and 17 OB boys (BMI=25.8+/-0.9 kg/m(2); age=11.4+/-0.3 years) (Experiment 1) and 12 NW boys (BMI=18.6+/-0.6 kg/m(2); age=12.1+/-0.3 years) (Experiment 2). On three separate mornings and in random order each of the boys consumed a noncaloric sweetened preload, glucose (837 kJ) or whey protein (837 kJ) (Experiment 1) or noncaloric preload, glucose (1.0 g/kg) or whey protein (1.0 g/kg) (Experiment 2) made up to 250 ml with water 2 h after the consumption of a fixed breakfast. Food intake from a pizza meal was measured 30 min (Experiment 1) or 60 min (Experiment 2) later. In Experiment 1, glucose suppressed FI (mean kJ+/-s.e.m.) in NW (3126+/-304) and OB boys (3116+/-286) compared with the control (NW, 4015+/-337 and OB, 3791+/-255). Whey protein suppressed FI in NW, but not in OB boys. Body weight, fat-mass and fat-free mass were positively associated with FI after all treatments in NW, but was not related to FI in OB boys. In Experiment 2, FI was suppressed by whey protein (2683+/-367) more than by glucose (3107+/-294) or the control (3585+/-361). NW and OB boys respond differently to whey-protein preloads, with time to next meal a factor in the response to both glucose and protein preloads.

Sugars and satiety: does the type of sweetener make a difference?

Background: Widespread use of high-fructose corn syrup (HFCS) in beverages has been linked to rising obesity rates. One hypothesis is that HFCS in beverages has little satiating power.Objective: The objective of the study was to compare the relative effect of commercial beverages containing sucrose or HFCS on hunger, satiety, and energy intakes at the next meal with the use of a within-subject design.Design: Thirty-seven volunteers (19 men, 18 women) aged 20–29 y consumed isocaloric cola beverages (215 kcal) sweetened with sucrose, HFCS 42, or HFCS 55. HFCS 42 contains 42% fructose, and HFCS 55 contains 55% fructose. Diet cola (2 kcal), 1%-fat milk (215 kcal), and no beverage were the control conditions. The 5 beverages were consumed at 1010 (2 h after a standard breakfast). Participants rated hunger, thirst, and satiety at baseline and at 20-min intervals after ingestion. A tray lunch (1708 kcal) was served at 1230, and energy intakes were measured. The free sugars content of sucrose-sweetened cola was assayed at the time of the study.Results: We found no differences between sucrose- and HFCS-sweetened colas in perceived sweetness, hunger and satiety profiles, or energy intakes at lunch. The 4 caloric beverages tended to partially suppress energy intakes at lunch, whereas the no-beverage and diet beverage conditions did not; the effect was significant (P < 0.05) only for 1%-fat milk. Energy intakes in the diet cola and the no-beverage conditions did not differ significantly.Conclusion: There was no evidence that commercial cola beverages sweetened with either sucrose or HFCS have significantly different effects on hunger, satiety, or short-term energy intakes.

Associations between postprandial insulin and blood glucose responses, appetite sensations and energy intake in normal weight and overweight individuals: a meta-analysis of test meal studies

It is unclear whether postprandial blood glucose or insulin exerts a regulatory function in short-term appetite regulation in humans. The aim of this study was to investigate, by use of meta-analysis, the role of blood glucose and insulin in short-term appetite sensation and energy intake (EI) in normal weight and overweight participants. Data from seven test meal studies were used, including 136 healthy participants (ALL) (92 normal weight (NW) and 44 overweight or obese (OW)). All meals were served as breakfasts after an overnight fast, and appetite sensations and blood samples were obtained frequently in the postprandial period. Finally, an ad libitum lunch was served. Data were analysed by fixed effects study level (SL) meta-regression analysis and individual participant data (IPD) regression analysis, using STATA software. In SL analysis, postprandial insulin response was associated with decreased hunger in ALL, NW and OW (P < 0.019), and with increased satiety in NW (P = 0.004) and lower subsequent EI in OW (P = 0.022). Multivariate IPD analysis showed similar associations, but only in NW for hunger, satiety and EI (P < 0.028), and in ALL for EI (P = 0.016). The only association involving blood glucose was the multivariate IPD analysis showing an inverse association between blood glucose and EI in ALL (P = 0.032). Our results suggest that insulin, but not glucose, is associated with short-term appetite regulation in healthy participants, but the relationship is disrupted in the overweight and obese. We conclude that the postprandial insulin response may be an important satiety signal, and that central nervous system insulin resistance in overweight might explain the blunted effect on appetite.

Body fat content and feeding level interact strongly in the short- and medium-term regulation of plasma leptin during underfeeding and re-feeding in adult sheep

Circulating leptin is regulated by food intake in the long, medium and short term; however, little is known about putative remnant effects of these successive regulations at any given time. To clarify this, two experiments were conducted in adult sheep, during which body condition parameters and plasma leptin were measured. During experiment 1, twenty ewes with normal body condition were either well fed (101 % of maintenance energy requirements (MER)) or underfed (41 % MER) for 166 d, then rapidly re-fed (at a mean of 208 % MER) for 3 d. Leptinaemia decreased after 14 d of underfeeding, remained depressed until day 166 and did not increase after 3 d re-feeding, whereas it was increased (+153 %; P < 0.05) by re-feeding the previously well-fed ewes. During experiment 2, twenty-four fat or lean ewes were either well fed (114 % MER) or underfed (52 % MER) for 94 d, and gradually re-fed for 2 d and maintained at a high feeding level (235 % MER) for 9 d. Underfeeding decreased leptinaemia in fat (from 4.19 to 2.63 ng/ml) but not lean ewes, and re-feeding increased leptinaemia after 5 d in lean previously well-fed (+123 %; P < 0.05) but not underfed ewes. In fat ewes, the impact of re-feeding was rapid (+144 %; P < 0.001 at 5 d) in previously well-fed ewes, whereas it was more gradual with a maximum at 11 d (+162 %; P < 0.01) in previously underfed ewes. In conclusion, leptinaemia is modulated by short-term energy intake level in interaction with long-term regulations involving nutritional history and body fatness, suggesting that a biological threshold of adiposity (about 20 %) is necessary to allow short- and medium-term leptin regulation.

Effect of short-duration physical activity and ventilation threshold on subjective appetite and short-term energy intake in boys

The purpose of this investigation was twofold: (1) to examine the role of low- to moderate-intensity, short-duration physical activity on subjective appetite and (2) to identify the role of and associations between ventilation threshold (VeT) and energy intake at a pizza lunch 30 min after glucose and whey protein drinks in normal weight boys. In 14 boys (age: 12.5±0.4 years) subjective appetite was measured before and after a 12 min walking protocol designed to determine physical fitness based on the VeT. On a separate occasion food intake (FI) and subjective appetite were measured in response to sweetened preloads of either a SPLENDA ® Sucralose control, glucose or whey protein made up to 250 ml with water, given in random order to each boy, 2 h after a standardized breakfast. Subjective average appetite and prospective food consumption scores increased after physical activity. VeT was positively associated with FI at a pizza lunch consumed 30 min after glucose and whey protein drinks. Glucose and whey protein reduced FI similarly at lunch compared with control. In conclusion, appetite is increased by low- to moderate-intensity, short-duration physical activity and FI following glucose and protein preloads is positively associated with fitness levels in boys.

Habitual physical activity differentially affects acute and short-term energy intake regulation in young and older adults

Energy intake (EI) regulation is impaired in older adults, but it is not known if habitual physical activity affects accuracy of EI regulation in older compared with young adults. We hypothesized that the ability to compensate for a high-energy yogurt preload beverage at a subsequent ad libitum meal (i.e. acute compensation) and over the course of the testing day (i.e. short-term compensation) would decrease with age, but the magnitude of the decline would be smaller in physically active compared with sedentary older adults. On two occasions, young active (n=15), young sedentary (n=14), older active (n=14) and older sedentary (n=11) subjects consumed either a high-energy yogurt preload beverage (YP: 500 ml, 1988 kJ, men; 375 ml, 1507 kJ, women), or no preload (NP), 30 min before an ad libitum test meal. EI at both ad libitum meals was measured, and total daily EI was determined on both testing days. Percent EI compensation for the YP was calculated for the test meal and testing day to determine acute and short-term compensation. Percent EI compensation at the test meal was significantly lower in the older compared with the young subjects (65+/-4 vs 81+/-4%, P=0.005). There was no effect of habitual physical activity level on acute compensation, and no age by physical activity level interaction (P=0.60). In contrast, short-term compensation was not different with age (87+/-5 vs 93+/-6%, older vs young, P=0.45), but was more accurate in active vs sedentary subjects (100+/-5 vs 79+/-6%, P=0.01). As with acute compensation, there was no age by physical activity interaction (P=0.39). Acute EI regulation is impaired in older adults, which is not attenuated by physical activity status. However, EI regulation over the course of a day is more accurate in active vs sedentary adults, which may facilitate long-term energy balance. Future work is needed to determine if higher energy expenditure in older active vs older sedentary adults improves long-term EI regulation.

Body mass and composition responses to short-term low energy intake are seasonally dependent in Steller sea lions (Eumetopias jubatus)

Steller sea lions (Eumetopias jubatus) were fed restricted iso-caloric amounts of Pacific herring (Clupea pallasi) or walleye pollock (Theragra chalcogramma) for 8-9 days, four times over the course of a year to investigate effects of season and prey composition on sea lion physiology. At these levels, the sea lions lost body mass at a significantly higher rate during winter (1.6 +/- 0.14 kg day(-1)), and at a lower rate during summer (1.2 +/- 0.32 kg day(-1)). Decreases in body fat mass and standard metabolic rates during the trials were similar throughout the seasons and for both diet types. The majority of the body mass that was lost when eating pollock derived from decreases in lipid mass, while a greater proportion of the mass lost when eating herring derived from decreases in lean tissue, except in the summer when the pattern was reversed. Metabolic depression was not observed during all trials despite the constant loss of body mass. Our study supports the hypothesis that restricted energy intake may be more critical to Steller sea lions in the winter months, and that the type of prey consumed (e.g., herring or pollock) may have seasonally specific effects on body mass and composition.

Effects on hunger and satiety, perceived portion size and pleasantness of taste of varying the portion size of foods: A brief review of selected studies

The portion size of foods has been identified as an important environmental factor known to affect short-term energy intake. Experiments that were conducted both in the free-living environment and in laboratory-based settings to investigate the effects of portion size on energy intake unanimously showed that as the portion size of food increased, so did subjects' energy intake. Despite the fact that the profound effects of portion size on energy intake are well documented, the mechanisms by which portion size affects energy intake are poorly understood. There is some evidence that sensory influences (e.g. visual and olfactory cues), cognitive factors (e.g. learning, social norms, monetary considerations), and post-ingestive consequences (e.g. sensations of hunger and fullness) related to the portion size of foods may interact to affect the amount of food that is consumed during a meal.

Effects of palatability and learned satiety on energy density influences on breakfast intake in humans

The present report explored firstly how palatability modified the effects of energy density (ED) on short-term food intake and changes in rated appetite within a single test meal, and secondly how repeated consumption altered these relationships. Experiment 1 contrasted disguised high (HED) and low (LED) versions of a food presented in bland and palatable forms. Mass consumed varied as an interaction of palatability and ED, with subjects eating least of the bland/HED version, suggesting some un-learned satiating effects. No such compensation for ED was seen in the palatable/HED condition, and overall energy intake increased with ED. Palatability had the expected stimulatory effect on appetite, but rated hunger decreased more rapidly as a function of energy consumed in the HED conditions. Experiment 2 introduced novel distinctive flavours to examine whether repeated experience of palatable HED and LED versions resulted in learned satiety. Participants ate the same mass of LED and HED versions on first exposure, but after two training days with each food, where they consumed a fixed amount, they subsequently ate a greater mass of the LED version, consistent with learned satiety. Increased intake was accompanied by a slower rate of decline in hunger in the LED condition. Despite these changes, energy intake remained higher with the HED version. Liking for the LED version was greater than the HED version at the end, possibly due to mild aversive qualities of eating a fixed portion of the HED food during training. Together these data suggest that energy density is the major determinant of short-term energy intake in the absence of orosensory cues predictive of energy differences, but that learning of flavour–energy associations can, to some extent, allow short-term energy consumption to be regulated.

Provision of Foods Differing in Energy Density Affects Long‐Term Weight Loss

The energy density (kilocalories per gram) of foods influences short-term energy intake. This 1-year clinical trial tested the effect on weight loss of a diet incorporating one or two servings per day of foods equal in energy but differing in energy density. Dietitians instructed 200 overweight and obese women and men to follow an exchange-based energy-restricted diet. Additionally, subjects were randomized to consume daily either one or two servings of low energy-dense soup, two servings of high energy-dense snack foods, or no special food (comparison group). All four groups showed significant weight loss at 6 months that was well maintained at 12 months. The magnitude of weight loss, however, differed by group (p=0.006). At 1 year, weight loss in the comparison (8.1+/-1.1 kg) and two-soup (7.2+/-0.9 kg) groups was significantly greater than that in the two-snack group (4.8+/-0.7 kg); weight loss in the one-soup group (6.1+/-1.1 kg) did not differ significantly from other groups. Weight loss was significantly correlated with the decrease in dietary energy density from baseline at 1 and 2 months (p=0.0001) but not at 6 and 12 months. On an energy-restricted diet, consuming two servings of low energy-dense soup daily led to 50% greater weight loss than consuming the same amount of energy as high energy-dense snack food. Regularly consuming foods that are low in energy density can be an effective strategy for weight management.

Short-term appetite and energy intake following imposed exercise in 9- to 10-year-old girls

Short-term effects of different intensities of exercise-induced energy expenditure on energy intake and hunger were compared in 19 girls (10.0±0.6 years) in three conditions: sedentary, low-intensity exercise and high-intensity exercise. The exercise conditions involved cycling at 50 and 75% of peak oxygen uptake, respectively, but were designed to evoke approximately 1.50 MJ of total expenditure, as estimated from continuously monitored heart rate. A maintenance breakfast of controlled energy intake was provided and ad libitum energy intake was measured at lunch and dinner. Differences in energy intake relative to expenditure, between 09:30 and 17:00, were calculated by subtracting energy expenditure from energy intake (energy difference). Hunger, fullness and prospective consumption were rated before and after meals and exercise sessions. Lunch energy intake was significantly less after low-intensity exercise than after high-intensity exercise. Energy expenditure was greater in the exercise conditions than when sedentary and the energy difference was more positive in the sedentary condition than in each of the exercise conditions. At mid-afternoon, rated prospective consumption was less after the high-intensity exercise. The imposition of energy expenditure through exercise of either low or high intensity resulted in no detectable increase in energy intake in the short term.

Oral supplements differing in fat and carbohydrate content: effect on the appetite and food intake of undernourished elderly patients

Background & aims: Since fat, relative to other macronutrients, has low satiety and high energy density, it may have therapeutic application for supplementing energy intake. This study compared the effect of isoenergetic (1050 kJ) high fat or high carbohydrate oral supplements, given at breakfast, on the short-term appetite and energy intake in undernourished elderly subjects. Methods: Sixteen hospitalised, undernourished (body mass index: 20±3 kg/m 2), elderly (77±8 yr) people were randomly allocated to a control or 1 of 2 supplement groups [fat: carbohydrate: protein (% energy) was 70:25:5 or 25:70:5]. In each group, energy intake (24-h food consumption) and appetite (visual analogue scales) were assessed over 3 consecutive days. Results: Mean energy intake significantly ( P=0.0035) increased following supplementation: high fat 6973 kJ/d, high carbohydrate 6906 kJ/d vs. control 6079 kJ/d but mean voluntary 24-h energy intake remained unaffected. Compared to controls, supplemented subjects experienced reduced hunger ( P=0.07) between breakfast and lunch, but showed no difference over the whole day ( P=0.55). Conclusions: Under these study conditions a 1050 kJ oral supplement, irrespective of macronutrient composition, does not cause voluntary short-term energy intake compensation in undernourished elderly people.

Increasing the portion size of a packaged snack increases energy intake in men and women

The objective of this study was to determine how the portion size of a packaged snack affects energy intake of the snack and of the subsequent meal. On five separate days, 60 subjects (34 women and 26 men) ate an afternoon snack and dinner in individual cubicles. For each snack, subjects were served one of five packages of potato chips (28, 42, 85, 128, or 170 g), which they consumed ad libitum directly from the unlabelled, opaque package. Subjects returned to the lab three hours later for a standard dinner, which was also consumed ad libitum. Results showed that snack intake increased significantly as the package size increased for both males and females ( p<0.0001). The combined energy intake from snack and dinner also increased as the package size increased. On average, when served the largest snack package compared to the smallest, subjects consumed an additional 596 kJ (143 kcal) at snack and dinner combined. Results from this study demonstrate that short-term energy intake increases with increasing package size of a snack. These data suggest that the availability of large packages of energy-dense snacks may be one of the environmental influences associated with excess energy intake.

THE TEMPORAL SCALE OF FORAGING DECISIONS IN BISON

Assessing the temporal scale under which gain is maximized is critical for the understanding of diet choice by animals. Classical foraging theory assumes that animals maximize long-term rates. Few studies have considered several temporal scales concur- rently, however, weakening tests of rate-maximizing models. We used contingency models based on maximization of short-term vs. long-term energy intake by bison (Bison bison). Model predictions were tested against field observations conducted during six periods of 1998: two periods in the winter, one in the spring, and three in the summer. During most of the year, foraging characteristics and plant attributes suggested that intake rate of bison should be limited by ingestion time over short periods of time, and by digestive constraints over long periods of time. Diet predictions varied across temporal scales for four of the six sampling periods. Selecting Agropyron spp., rather than Carex atherodes, during these periods would result in an increase of daily energy intake by as much as 15 565 kJ (i.e., 7.4% of daily gains) but would necessitate a longer daily foraging time. We observed, instead, that bison preferred C. atherodes to Agropyron spp., suggesting that patterns of diet selection by bison were more consistent with maximization of short-term than of long- term energy intake. We thus provide some evidence that, contrary to established principles of classic optimality models, the foraging decisions of bison reduce potential long-term gains by maximizing short-term gains.

Food intake in rats is unaffected by the profile of dietary essential fatty acids

Food intake may be differentially responsive to the type of fat in the diet. The present investigation sought to evaluate the energy intake of rats maintained on either a low-fat or a high-fat diet mixed with an oil rich in either linoleic (18:2; n−6; safflower oil) or linolenic (18:3; n−3; flaxseed oil) acid. In Experiment 1, rats ( n=28) consumed low-fat versions of either the safflower oil diet or the flaxseed oil diet, each at 9.28% fat (wt/wt). In Experiment 2, different rats ( n=28) consumed high-fat versions of these diets, each at 23.6% fat (wt/wt). Within each experiment, the energy intake of rats receiving the safflower oil diet was compared to the energy intake of rats receiving the flaxseed oil diet. Food intake was measured under short-term, long-term and food-deprived conditions. In Experiment 1, short-term energy intakes were not different between the groups, thus demonstrating equal acceptance of the test diets. There were no consistent differences in long-term energy intakes between the safflower group and the flaxseed group. In addition, there were no differences in energy intake under the food-deprivation condition. Results from Experiment 2 paralleled those of Experiment 1. Taken together, the present results suggest that the essential fatty acid profile of the maintenance diet does not influence food intake when nutritive oils are the predominant fatty acid source.

Comparison of high-fat and high-carbohydrate foods in a meal or snack on short-term fat and energy intakes in obese women

The present study aimed to compare the action of high-fat and high-carbohydrate (CHO) foods on meal size (satiation) and post-meal satiety in obese women. A within-subjects design was used; each participant received all four nutritional challenges. Fifteen healthy obese women (age 21-56 years, BMI 35-48 kg/m2) participated; thirteen completed all four test days. On two test days, participants were exposed to a nutritional challenge comprising an ad libitum high-fat or high-CHO lunch. On the other two test days they were exposed to a challenge comprising an ad libitum sweet high-fat or high-CHO mid-afternoon snack. Energy and macronutrient intakes were measured at each eating episode. Visual analogue rating scales were completed periodically to record subjective feelings of appetite. When offered a high-CHO selection of foods at lunch and mid-afternoon participants consumed less energy than when offered a high-fat selection. However, post-meal satiety was similar. Total test-day energy intake was significantly higher when high-fat foods were consumed at lunch, but not as a snack. Consumption of high-fat foods at a lunch and snack increased the amount of fat consumed over the whole test day. In conclusion, energy intake of an eating episode was influenced by nutrient composition in this group of obese women. Consumption of high-fat foods at lunch or as a snack led to overconsumption relative to high-CHO foods. However, high-fat foods at meals may have greater potential to influence daily intake than at snacks, probably because meals are larger eating episodes and therefore give greater opportunity to overconsume.

Regulation of metabolism and body fat mass by leptin.

The relative stability of body weight over the long term and under a variety of environmental conditions that alter short-term energy intake and expenditure provides strong evidence for the regulation of body energy content. The lipostatic theory of energy balance regulation proposed 40 years ago that circulating factors, generated in proportion to body fat stores, acted as signals to the brain, eliciting changes in energy intake and expenditure. The discovery of leptin and its receptors has now provided a molecular basis for this theory. Leptin functions as much more than an adipocyte-derived signal of lipid stores, however. Although suppression of food intake is an important centrally mediated effect of leptin, considerable evidence indicates that leptin also functions both directly and indirectly, via the brain, to orchestrate complex metabolic changes in a number of organs and tissues, altering nutrient flux to favor energy expenditure over energy storage.

The effects of specific nutrients on the regulation of feeding behaviour in human subjects.

Regulation of short-term energy intake involves the balance of positive drives to eat arising from the sight, smell and palatability of food with negative feedback signals from learned associations, gastrointestinal and metabolic signals. The stomach and small intestine are major sites in the feedback inhibition of food intake and subsequent period of appetite suppression. The present paper reviews the evidence that not only does the nature of the regulatory signal suppressing food intake depend on the type and energy content of nutrient consumed, but also the specific chemical composition of the nutrients and the site at which they are delivered. It is evident that feedback inhibition of feeding can be modulated by the particular chemical structure of nutrients (e.g. specific sugar or triacylglycerol structures). These differences in response are likely to be a consequence of differences in physical properties of particular nutrients depending on their chemical structure, and may also result from different receptor affinities for specific dietary structures. Moreover, the site of administration of nutrients can also profoundly affect the size and nature of the subsequent feeding response, suggesting that feed-forward interactions occur between the taste of foods and gastrointestinal stimulation.