Early postnatal low-protein nutrition, metabolic programming and the autonomic nervous system in adult life

Background

Dietary fibers have been proposed to play a role in cardiovascular risk as well as body weight management. Flaxseeds are a good source of dietary fibers, and a large proportion of these are water-soluble viscous fibers.

Method

Here, we examine the effect of flaxseed dietary fibers in different food matrices on blood lipids and fecal excretion of fat and energy in a double-blind randomized crossover study with 17 subjects. Three different 7-d diets were tested: a low-fiber control diet (Control), a diet with flaxseed fiber drink (3/day) (Flax drink), and a diet with flaxseed fiber bread (3/day) (Flax bread). Total fat and energy excretion was measured in feces, blood samples were collected before and after each period, and appetite sensation registered 3 times daily before main meals.

Results

Compared to control, Flax drink lowered fasting total-cholesterol and LDL-cholesterol by 12 and 15%, respectively, (p < 0.01), whereas Flax bread only produced a reduction of 7 and 9%, respectively (p < 0.05). Fecal fat and energy excretion increased by 50 and 23% with Flax drink consumption compared to control (p < 0.05), but only fecal fat excretion was increased with Flax bread compared to control (p < 0.05).

Conclusion

Both Flax drink and Flax bread resulted in decreased plasma total and LDL-cholesterol and increased fat excretion, but the food matrix and/or processing may be of importance. Viscous flaxseed dietary fibers may be a useful tool for lowering blood cholesterol and potentially play a role in energy balance.

Trial Registration

ClinicalTrials.gov: NCT00953004     

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/m2), 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.     

The effect of guar gum addition to a semisolid meal on appetite related to blood glucose,in dieting men

OBJECTIVE: To investigate whether addition of modified guar gum (GG) to a low-energy semisolid meal might be effective on appetite by modifying the response of blood glucose and other blood parameters. DESIGN: Three intervention periods of 2 weeks each, separated by washout periods of 4 weeks. Randomized and cross-over design. SUBJECTS: Fifteen overweight male subjects (mean+/-s.d.; age, 44+/-9 y; body mass index, 28.6+/-1.8 kg/m(2)). INTERVENTION: Subjects consumed a low-energy diet divided over three times a day, consisting of a semisolid meal with (SSM+) or without (SSM) addition of 2.5 g GG, or a solid meal (SM) with the same energy content (947 kJ) and macronutrient composition, plus a dinner of the subject's own choice. At the end of each intervention, time and number of meal initiations, dynamics of blood glucose and other blood parameters, and appetite ratings such as hunger and satiety were determined in a time-blinded situation. RESULTS: The changes in blood glucose from meal initiation to blood glucose peak and from peak to nadir were smaller with SSM+ and SM compared to SSM. Satiety before the third meal was higher with SSM+ and SM compared to SSM (P<0.01). Meal pattern, general appetite and total energy intake were similar for all treatments. CONCLUSIONS: We conclude that, similar to SM, SSM+ resulted in a more moderate change in blood glucose compared to SSM and positively affected satiety before the third meal, while general appetite, total energy intake and meal pattern did not differ.     

Lupin-enriched bread increases satiety and reduces energy intake acutely

BACKGROUND: Protein and fiber may be important determinants of satiety. Lupin kernel flour is a novel food ingredient that is rich in protein and fiber. OBJECTIVE: The objective was to investigate the effects of lupin kernel flour-enriched bread (LB) on satiety and energy intake in humans. DESIGN: Two randomized controlled crossover trials were performed to compare the acute effects of LB with those of white bread (WB). In study 1, the subjects (n = 16) completed 4 treatments 1 wk apart: WB breakfast (as toast) and WB lunch (as sandwiches), WB breakfast and LB lunch, LB breakfast and WB lunch, and LB breakfast and LB lunch. Energy intake at all breakfast meals was matched (1655 kJ), and ad libitum energy intake at lunch, 3 h after breakfast, was measured. In study 2, the subjects (n = 17) completed 2 treatments 1 wk apart: WB breakfast and LB breakfast (each 1655 kJ). Blood samples were taken at baseline and at regular intervals for 3 h after breakfast. RESULTS: In study 1, the LB breakfast resulted in significantly higher self-reported satiety (P < 0.001) and lower energy intake (kJ) at lunch (-488; 95% CI: -798, -178) than did the WB breakfast. The LB lunch resulted in a significantly lower within-meal energy intake (kJ) at lunch (-1028; 95% CI: -1338, -727) than did the WB lunch. In study 2, compared with the WB breakfast, the LB breakfast significantly altered the 3-h postmeal plasma ghrelin response (P = 0.04) and resulted in significantly lower mean 3-h plasma ghrelin concentrations (P = 0.009). CONCLUSION: A novel food enriched in protein and fiber derived from lupin kernel flour significantly influences energy intake acutely.     

Effects of flax fiber on laxation and glycemic response in healthy volunteers

We investigated whether a flax supplement taken orally or baked in a bakery product would effect the physiological responses characteristic of soluble and insoluble fiber, i.e., laxation and glycemic response, respectively. In Study 1, 26 healthy young adults consumed up to 15 g of fiber from a proprietary flax fiber supplement or as a psyllium supplement for 2 weeks once usual fecal weights were established. Changes in dietary fiber intake and acceptability of both products were evaluated. An increase in fecal weight was found with both fiber treatments. Supplemental fiber at intakes of 9.0 g/day (flax) and 10.4 g/day (psyllium) gave fecal bulking capacity of about 2.9 and 4.8 g of fecal weight/g of fiber, respectively. In Study 2, the effect of flax bread versus control white bread on glycemic response was studied. Eleven fasting subjects completed four test periods (duplicate trials of each bread) under standardized glycemic testing conditions. Paired t tests were used to analyze test compared with control peak blood glucose values (6.6 +/- 0.9 mmol/L compared with 6.9 +/- 0.7 mmol/L, P < .05, respectively) and area under the curve (AUC) (669 +/- 53 compared with 693 +/- 57, P = .015, respectively). Peak blood glucose values and AUC were improved by ingestion of flax fiber in healthy subjects. In conclusion, a flax fiber supplement provides the benefits of soluble and insoluble fiber.     

Increased satiety after intake of a chocolate milk drink compared with a carbonated beverage, but no difference in subsequent ad libitum lunch intake

The rising rate of obesity has been blamed on increased consumption of sugar-sweetened soft drinks, such as carbonated sodas, which fail to satisfy hunger. The objective of the present study was to compare the effect on appetite and energy intake of a sugar-sweetened beverage (cola) and a chocolate milk drink, matched for energy content and volume. It was hypothesised that chocolate milk may be more satiating because of its protein content. Twenty-two healthy young men (age 23 (SD 1 x 8) years) of normal weight (BMI 22 x 2 (SD 1 x 5) kg/m2) were recruited to the randomised cross-over study. Visual analogue scales were used to record subjective appetite ratings every 30 min on each of two test days. A drink of 500 ml cola or chocolate milk (900 kJ) was ingested 30 min before an ad libitum lunch. Satiety and fullness were significantly greater (P=0 x 0007, P=0 x 0004, respectively) 30 min after chocolate milk than after cola. Ratings of prospective consumption and hunger were significantly greater after cola than after chocolate milk, both immediately after preload intake (P=0 x 008, P=0 x 01, respectively) and 30 min afterwards (P=0 x 004, P=0 x 01, respectively). There was no significant difference (P=0 x 42) in ad libitum lunch intake after ingestion of chocolate milk (3145 (SD 1268) kJ) compared with cola (3286 (SD 1346) kJ). The results support the hypothesis that sweetened soft drinks are different from milk products in their impact on short-term hunger and satiety, although differences in subjective appetite scores were not translated into differences in energy intake.     

Flaxseed reduces plasma cholesterol levels in hypercholesterolemic mouse models

OBJECTIVE: We examined the effects of whole ground flaxseed added to a Western diet on plasma and hepatic lipids and hepatic gene expression in male and female human apolipoprotein B-100 transgenic (hApoBtg) mice which have a plasma lipid profile more closely resembling man than wild type mice and in mice lacking the low density lipoprotein receptor (LDLr) and apolipoprotein B mRNA editing enzyme complex 1 (LDLr(-/-)/apobec(-/-)). METHODS: The Westernized control diet containing 0.1% cholesterol and 30% kcal as fat was fed for 10 days to hApoBtg mice and for 14 days to LDLr(-/-)/apobec(-/-) mice. Animals from each genetic background were then divided into 2 groups based on gender and mean plasma total cholesterol (TC). The hApoBtg and LDLr(-/-)/apobec(-/-) mice either continued on the control diet for a total of 31 and 35 days, respectively or were fed 20% w/w whole ground flaxseed (flax) with comparable caloric, macronutrient and fiber content for 21 days. Blood was obtained after a 4 hour fast from all mice prior to feeding both control and flax diets, after 10 days on the flax diet, and after 21 days on the flax at which time all mice were exsanguinated. RESULTS: The control diet increased TC by >100 mg/dl in the hApoBtg with a greater increase observed in males and by 800 mg/dl in mice lacking the LDLr. After 3 weeks, the flax diet significantly reduced plasma TC by 19% and 22% in hApoBtg and LDLr(-/-)/apobec(-/-), respectively and non-high density lipoprotein cholesterol (non-HDL-C) by 24% in both models (p for all <0.05). Flax significantly reduced hepatic cholesterol in hApoBtg by 32% and 47% in males and females, respectively and LDLr(-/-)/apobec(-/-) mice by 66%. Flax had no effect on the expression of the following hepatic genes: LDLr, 3-hydroxy-3-methylglutaryl (HMG) CoA reductase, phospholipid transfer protein, cholesterol 7alpha hydroxylase, fatty acid synthase, and acyl CoA oxidase in either mouse model. CONCLUSIONS: Flaxseed reduces plasma and hepatic cholesterol in hApoBtg mice, but had no effect on hepatic lipogenic genes and was equally effective in mice lacking LDLr. The combined data suggest that the lipid lowering effect of flax is not hepatic mediated and may be at the level of cholesterol absorption and/or bile acid reabsorption.     

Energy intake and appetite are related to antral area in healthy young and older subjects

BACKGROUND: Gastric distension reduces food intake, and antral, rather than proximal, gastric distension may be the dominant mechanism in the induction of appetite-related sensations. Healthy aging is associated with reduced appetite. OBJECTIVE: We examined the effects of different energy preloads on appetite, plasma cholecystokinin, antral area, and subsequent energy intake in healthy older and young subjects. DESIGN: On 3 separate days, 12 young and 12 older subjects consumed 400 mL of a drink containing either 0 kcal (water), 250 kcal, or 750 kcal 70 min before a buffet-style meal. RESULTS: Hunger was less in the older than in the young subjects (P < 0.001). Both nutrient preloads reduced hunger and increased fullness more than did water (P < 0.02), and older subjects were more full than were the young (P < 0.05). Antral area was greater after the nutrient preloads than after water (P = 0.001) and greater in the older than in the young subjects (P = 0.005). In both groups, food intake was suppressed in an energy-dependent manner (P = 0.008). Plasma cholecystokinin was greater in the older than in the young subjects (P = 0.003). Immediately before the meal, hunger (r = -0.59) and energy intake (r = -0.90) were inversely related and fullness (r = 0.66) was directly related to antral area (all: P < 0.001). Antral area, but not plasma cholecystokinin, was a predictor of subsequent energy intake. CONCLUSION: In healthy young and older subjects, the suppression of subsequent energy intake by a liquid preload is nutrient dependent and comparable, and both satiation and satiety are related to antral area and (presumably) antral distension.     

Beverages containing soluble fiber, caffeine, and green tea catechins suppress hunger and lead to less energy consumption at the next meal

Previous research has shown that beverages containing soluble fibers can decrease energy intake at the next meal among normal weight participants. Caffeine and green tea catechins have separately been associated with increased satiety. The present study examined the satiating power of a beverage containing soluble fiber as well as a beverage containing the same fiber, caffeine and green tea catechins. These two test beverages were evaluated in comparison to an equal calorie control beverage as well as a no-beverage control condition. All beverage preloads were presented three times for a total of 0.28-0.35MJ and 0-30g fiber. Dependent measures were appetite ratings and calorie intake at a test meal. The no-beverage condition was associated with the highest ratings for hunger and the lowest ratings for fullness when compared to the other three beverage conditions. Of the three beverage conditions, the beverage containing the fiber, green tea catechins, and caffeine created the lowest hunger and the highest fullness ratings. That condition was also associated with the lowest energy intake at the next meal. The present findings indicate that the beverage containing caffeine and green tea catechins in combination with soluble fiber decrease appetite and energy intake relative to a beverage with equal caloric content.     

Fiber Intake and Risk of Nasopharyngeal Carcinoma: A Case-Control Study

Some studies examined the inverse relation between nasopharyngeal carcinoma (NPC) risk and dietary fibers in endemic populations. By means of a hospital-based case-control study, we verified whether this association was also present in Italy in connection with various types of dietary fibers. Cases were 198 patients with incident, histologically confirmed, NPC admitted to major teaching and general hospitals during 1992–2008. Controls were 594 patients admitted for acute, nonneoplastic conditions to the same hospital network of cases. Information was elicited using a validated food frequency questionnaire including 78 foods, food groups, or dishes. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated for quartiles of intake of different types of fiber after allowance for energy intake and other potential confounding factors. Total fiber intake was inversely related to risk of NPC (OR = 0.58 for the highest vs. the lowest quartile of intake; 95% CI: 0.34–0.96). We found an inverse association for total soluble (OR = 0.58; 95% CI: 0.35–0.96) and total insoluble fiber (OR = 0.56; 95% CI: 0.33–0.95), in particular cellulose (OR = 0.57; 95% CI: 0.33–0.96), and lignin (OR = 0.51; 95% CI: 0.31–0.85). In conclusion, this study suggests that dietary intake of soluble and insoluble fibers is inversely related to NPC risk in a nonendemic southern population.     

Appetite sensations as a marker of overall intake

The aim of this study was to evaluate the clinical utility of appetite sensations to characterize individual overall energy intake. A group of men (n 28) and women (n 23) was recruited to record their 'desire to eat', 'hunger', 'fullness' and 'prospective food consumption' (PFC) on visual analogue scales before a standardized meal test, immediately after and every 10 min for a period of 1 h after the meal. The 1 h post-meal area under the curve (1 h AUC) and the satiety quotient (SQ) were calculated for all appetite sensations. In a second visit, all participants were invited to eat three meals in order to measure total energy intake (TEI) and food preferences. Metabolic rate (MR) was also assessed to derive daily relative energy intake (REI) by subtracting this variable from TEI (TEI-MR=REI). The Three-Factor Eating Questionnaire scores were also calculated for all participants. One h AUC for fullness was the appetite sensation most strongly associated with TEI and REI (r-0.42, P< or =0.003 and r-0.32, P< or =0.05, respectively). SQ for fullness was the only predictor of TEI and REI (r-0.42, P< or =0.0003 and r-0.30, P< or =0.05, respectively). Restraint, disinhibition and hunger scores were not associated with appetite sensation variables. These results suggest that the fullness dimension seems to be a useful appetite sensation to predict long-term TEI and REI. Thus, assessment of appetite sensation such as fullness in response to a fixed load may be useful to evaluate individual overall energy intake.     

The effect of flaxseed supplementation in processed foods on serum fatty acids and enterolactone

OBJECTIVE: The purpose was to study the effects of flaxseed supplementation as a part of daily diet on serum lipids, fatty acids and plasma enterolactone. DESIGN: Eighty volunteers participated in this clinical nutrition study which was carried out in a controlled, double-blind and cross-over manner. The subjects were randomized to diet sequences AB or BA. Diet A meals contained 1.3 g/100 g ground flaxseed and 5 g/100 g flaxseed oil. Also 3-4 g/100 of inulin and wheat fiber was added. AB diet with non-supplemented foods served as control. Test subjects were on both diets for 4 weeks separated by a 4-week wash-out period. Fifteen test subjects continued an open part of the study for 4 additional months. INTERVENTIONS: The dietary intake, basic blood values, serum lipids, fatty acids and enterolactone were measured at baseline, after both intervention periods and during the open study, at baseline and after 2 and 4 months. Serum thiocyanate and blood cadmium were controlled after both intervention periods. RESULTS: The percentage of flaxseed supplemented test food out of total dietary intake was 20% of energy. The test food contained significantly higher amounts of fiber, polyunsaturated fatty acids (PUFAs) and especially alpha-linolenic acid than the control food. No significant changes were observed in the basic laboratory values or in blood lipids. There was a significant increase in serum alpha-linolenic acid, eicosapentaenoic acid and docosapentaenoic acid. Serum enterolactone concentration was doubled during flaxseed supplementation. Serum thiocyanate and blood cadmium values did not exceed reference values and there was no difference between the diets. CONCLUSIONS: In this study we were able to show that, by adding ground flaxseed and flaxseed oil to one or two daily meals, it is possible to obtain significant effects on serum levels of enterolactone and alpha-linolenic acid. SPONSORSHIP: The study was sponsored by the National Technology Agency of Finland (Tekes).     

Short-term effects of different amounts of protein, fats, and carbohydrates on satiety.

This study investigated the satiating efficiencies of proteins, fats, and carbohydrates (CHOs). Twenty-nine female, normal-weight subjects each received 10 liquid breakfasts, which varied in energy and macronutrient contents. Besides a zero condition [0.3 MJ (8 kcal)], there were three energy levels [0.42, 1.05, and 1.67 MJ (100, 250, and 400 kcal)] combined with three dominant sources of macronutrients (99% of energy from CHO, 92% of energy from fat, and 77% of energy from protein). After breakfast the subjects were not allowed to eat or drink (except water) for 3.5 h. They then recorded their voluntary food intake for the remainder of the day. Subjects also rated their subjective feelings concerning food intake on five different types of appetite. The results showed that neither energy content nor macronutrient composition of the liquid breakfasts had any effect on energy and macronutrient intake during lunch and the remainder of the day. Ratings of different types of appetite showed an increasing satiating effect with increasing energy content of the breakfasts. Proteins, fats, and CHOs had similar effects on appetite.     

Effects of NUTRIOSE® dietary fiber supplementation on body weight, body composition, energy intake, and hunger in overweight men

The objective of the present study was to determine the effectiveness of a soluble dietary fiber, NUTRIOSE(?), on body weight, body composition, energy intake and hunger in overweight Chinese men. The volunteers were randomized in double-blind fashion to 250 ml fruit juice supplemented with NUTRIOSE(?) (Test, n = 60) or a maltodextrin (Control, n = 60) at a dosage of 17 g twice daily for 12 weeks. Body weight, body composition were performed at 0, 4, 8 and 12 weeks while daily energy intake and hunger were assessed every 3 days. Test subjects had reductions in body weight (1.5 kg, P < 0.001), body mass index (0.5 kg/m(2), P < 0.001) and body fat percentage (0.3%, P < 0.001) versus Controls. NUTRIOSE(?) supplementation resulted in a lower daily energy intake (3,079 kJ/day, P < 0.001) with group differences noted as early as 3 days. Test subjects reported less hunger across the study period versus Controls (P < 0.01). NUTRIOSE(?) supplementation for 12 weeks results in body composition improvements and reduces body weight, energy intake and hunger in overweight men.     

A Mediterranean-like breakfast affects energy intake and appetite-related feelings

Energy intake and appetite feelings after the consumption of two different types of breakfast, a high-fiber, traditional, Mediterranean-type breakfast and a low-fiber, Western-type breakfast were compared. Sixteen non-obese young men received the two treatments on separate days: the Mediterranean- and the Western-type breakfasts were isocaloric, similar in volume and macronutrient content, but different in fiber content. Following a 4-hour fast, subjects offered an ad libitum lunch. Food consumed and subjective feelings of hunger, fullness, and desire to eat were evaluated. Energy intake in the ad libitum lunch was significantly lower after the Mediterranean-type, compared to the Western-type breakfast, adjusting for previous day’s energy intake (1488?±?468 versus 1674?±?416?kcal, respectively), whereas no energy compensation was made throughout the day. Furthermore, those who had the Mediterranean-type breakfast reported lower values in the desire to eat during study's course. These findings propose a fulfilling effect of a traditional, Mediterranean, high in fiber breakfast.     

The ability of habitual exercise to influence appetite and food intake in response to high- and low-energy preloads in man

The present study tested the hypothesis that habitual exercisers demonstrate an increased accuracy of regulation of food intake in compensation for previous dietary energy intake. Twenty-three lean healthy male subjects were divided into two groups on the basis of their habitual exercise levels: non-exercisers (no exercise sessions/week, n 9), and exercisers (>two exercise sessions of 40 min or more/week, n 14). The appetite response to covert liquid preloads of high (2513 kJ) energy (HE) and low (1008 kJ) energy (LE) was investigated Sixty minutes after the preload subjects were offered an ab libitum buffet-style meal and energy intake (EI) was calculated. Subjective hunger and satiety were assessed throughout using self-rated visual-analogue scales. Buffet EI in non-exercisers was not significantly different following the LE or HE preloads (mean compensation 7 %), but the exercise group significantly reduced their energy intake following the HE, compared with the LE, preload (mean compensation 90 %; P=0.0035). A broadly similar pattern of response was observed for both moderate (two to three sessions/week, n 7) and high exercisers (>four sessions/week, n 7). There were no significant differences between hunger or satiety ratings following HE or LE preloads for either group. However non-exercisers scored significantly higher on their self-ratings of hunger at the start of the study, before preload consumption, compared with the exercisers (P<0.01). These findings demonstrate that habitual exercisers have an increased accuracy of short-term regulation of food intake in compensation for preload manipulation, and provide additional support for advocating regular exercise in the prevention of overweight and obesity.     

Effects of a cereal rich in soluble fiber on body composition and dietary compliance during consumption of a hypocaloric diet

OBJECTIVES: To investigate the effects of oats, a cereal rich in soluble fiber, on body composition changes and dietary compliance during consumption of a weight loss diet. METHODS: Subjects were 41 healthy men and women aged 18 to 78 years. Weight maintenance energy requirements were established over two weeks during consumption of a control diet with low soluble fiber content. Subjects then consumed a hypocaloric diet for six weeks, either consuming a low soluble fiber control diet or a diet containing 45 g/1000 kcal rolled oats, a whole grain cereal rich in soluble fiber (mean energy deficit -895+/-18 kcal/day relative to weight maintenance energy requirements). Changes in body fat and fat-free mass were determined by underwater weighing, and dietary compliance was assessed using the urinary osmolar excretion rate technique. In a final phase of the study, subjects ate ad libitum for six months, and changes in body weight and composition were monitored. RESULTS: There was no significant effect of the oat-containing diet on body weight or composition changes during the hypocaloric regimen or in the subsequent ad libitum period. In addition, fecal energy excretion was not significantly different between groups. However, there were non-significant trends indicating reduced hunger in the oat group compared to controls (frequency of hunger 2.5+/-0.5 vs. 3.6+/-0.4, P=0.1). In addition, fewer oat subjects were non-compliant (four versus seven subjects dropped out or had urinary osmolar excretions greater than 130% of values predicted from dietary intake), but again the difference was not significant. CONCLUSIONS: These results suggest that use of a cereal rich in soluble fiber in a closely monitored hypocaloric feeding regimen does not improve weight loss or dietary compliance. Further studies are needed to examine the possibility that cereals containing soluble fiber may have effects on hunger and dietary compliance that could be important in less tightly controlled protocols than the one described here.     

Whey protein consumption after resistance exercise reduces energy intake at a post-exercise meal

Purpose

Protein consumption after resistance exercise potentiates muscle protein synthesis, but its effects on subsequent appetite in this context are unknown. This study examined appetite and energy intake following consumption of protein- and carbohydrate-containing drinks after resistance exercise.

Methods

After familiarisation, 15 resistance training males (age 21 ± 1 years, body mass 78.0 ± 11.9 kg, stature 1.78 ± 0.07 m) completed two randomised, double-blind trials, consisting of lower-body resistance exercise, followed by consumption of a whey protein (PRO 23.9 ± 3.6 g protein) or dextrose (CHO 26.5 ± 3.8 g carbohydrate) drink in the 5 min post-exercise. An ad libitum meal was served 60 min later, with subjective appetite measured throughout. Drinks were flavoured and matched for energy content and volume. The PRO drink provided 0.3 g/kg body mass protein.

Results

Ad libitum energy intake (PRO 3742 ± 994 kJ; CHO 4172 ± 1132 kJ; P = 0.007) and mean eating rate (PRO 339 ± 102 kJ/min; CHO 405 ± 154 kJ/min; P = 0.009) were lower during PRO. The change in eating rate was associated with the change in energy intake (R = 0.661, P = 0.007). No interaction effects were observed for subjective measures of appetite. The PRO drink was perceived as creamier and thicker, and less pleasant, sweet and refreshing (P < 0.05).

Conclusion

These results suggest whey protein consumption after resistance exercise reduces subsequent energy intake, and this might be partially mediated by a reduced eating rate. Whilst this reduced energy intake is unlikely to impair hypertrophy, it may be of value in supporting an energy deficit for weight loss.

     

Potato Fibers Have Positive Effects on Subjective Appetite Sensations in Healthy Men,but Not on Fecal Fat Excretion: A Randomized Controlled Single-Blind Crossover Trial

Dietary fibers can affect appetite and gut metabolism, but the effect of the novel potato fibers FiberBind and rhamnogalacturonan I (RG-I) is unknown. We, therefore, aimed to investigate the effect of daily intake of FiberBind and RG-I on appetite sensations and fecal fat excretion. In a single-blinded, randomized, three-way crossover trial, wheat buns with FiberBind, RG-I, or low fiber (control) were consumed by 18 healthy men during a 21-day period. Appetite sensation and blood samples during a 3 h meal test, fecal fat content, and ad libitum energy intake were assessed after each period. Compared to RG-I and control, FiberBind caused a higher composite satiety score (6% ± 2% and 5% ± 2%), lower prospective food consumption (5% ± 2% and 6% ± 2%), and lower desire to eat (7% ± 3% and 6% ± 3%) (all p < 0.05). FiberBind also caused higher satiety (6% ± 2%) and fullness (9% ± 3%) compared to RG-I (all p < 0.01). No effects on fecal fat excretion or energy intake were found. The RG-I fiber caused higher postprandial glucose concentration compared to FiberBind (p < 0.05) and higher insulin concentration at 180 min compared to control (p < 0.05). Compared to the control, RG-I and FiberBind lowered peak insulin concentration (both p < 0.05) and delayed time to peak for glucose (both p < 0.05). In conclusion, FiberBind intake could be beneficial for appetite regulation, but neither FiberBind nor RG-I affected fecal fat excretion or energy intake.     

Effect of dairy calcium or supplementary calcium intake on postprandial fat metabolism, appetite, and subsequent energy intake

BACKGROUND: High calcium intake has been shown to increase fecal fat excretion. OBJECTIVE: Our aim was to examine whether a high calcium intake from dairy products or from supplements affects postprandial fat metabolism and appetite through fat malabsorption. DESIGN: Four different isocaloric meals were tested in 18 subjects according to a randomized crossover design. The test meals contained high (HC meal: 172 mg/MJ), medium (MC meal: 84 mg/MJ), or low (LC meal: 15 mg/MJ) amounts of calcium from dairy products or a high amount of calcium given as a calcium carbonate supplement (Suppl meal: 183 mg/MJ). Concentrations of plasma total triacylglycerol, chylomicron triacylglycerol, serum total cholesterol, HDL cholesterol, cholecystokinin, glucagon-like peptide 1, ghrelin, peptide YY, glucose, and insulin and appetite sensation were measured before and at regular intervals until 420 min postprandially. RESULTS: Dairy calcium significantly diminished the postprandial lipid response. The baseline adjusted area under the curve for chylomicron triacylglycerol was approximately 17% lower after the MC meal (P = 0.02) and approximately 19% lower after the HC meal (P = 0.007) than after the LC meal and approximately 15% lower after the MC meal (P = 0.0495) and approximately 17% lower after the HC meal (P = 0.02) than after the Suppl meal. No consistent effects of calcium on appetite sensation, or on energy intake at the subsequent meal, or on the postprandial responses of cholecystokinin, glucagon-like peptide 1, ghrelin, peptide YY, insulin, or glucose were observed. CONCLUSIONS: Increased calcium intakes from dairy products attenuate postprandial lipidemia, most probably because of reduced fat absorption, whereas supplementary calcium carbonate does not exert such an effect. This may be due to differences in the chemical form of calcium or to cofactors in dairy products. Calcium did not affect appetite sensation, glucose metabolism, or gut hormone secretion.