Predictive Validity of Image-Based Motivation-to-Eat Visual Analogue Scales in Normal Weight Children and Adolescents Aged 9-14 Years

Paper-based motivation-to-eat visual analogue scales (VASs) developed for adults are widely used in the pediatric age range. The VAS is comprised of four domains: hunger, fullness, desire to eat, and prospective food consumption. The purpose of the present study was to determine agreement between the traditional paper-based VAS and a novel digital VAS (with and without images), as well as the novel digital VAS's predictive validity for subsequent food intake (FI) in 9-14-year-old children and adolescents. Following an overnight fast and 3 h after consuming a standardized breakfast at home, children and adolescents (n = 17) completed three different VAS instruments (VAS_paper, VAS_images, VAS_no-images) in a randomized order at five time-points: 0 min (baseline), 5 min (immediately after consuming a 147 kcal yogurt treatment), 20 min, 35 min (immediately before an ad libitum lunch), and 65 min (immediately post ad libitum lunch). All three instruments were comparable, as shown by low bias and limits of agreement on Bland-Altman plots, moderate to excellent intraclass correlation coefficients for all domains at all time-points (ICC = 0.72-0.98), and no differences between the incremental area under the curve for any of the domains. All three instruments also showed good predictive validity for subsequent FI, with the strongest relationship observed immediately before the ad libitum lunch (p = 0.56-0.63). There was no significant association between subjective thirst and water intake, except with VAS_no-images at baseline (r = 0.49, p = 0.046). In conclusion, the present study suggests that a novel image-based digital VAS evaluating motivation-to-eat is interchangeable with the traditional paper-based VAS, and provides good predictive validity for next-meal FI in 9-14-year-old normal weight children and adolescents.

The effect of dairy products and non-dairy snacks on food intake, subjective appetite and cortisol levels in children: a randomized control study

Dairy snacks are available in various physical forms and their consumption is linked to improved metabolic health. The objective of this study was to determine the effect of dairy snacks of different physical forms on short-term food intake (FI), subjective appetite, and the stress hormone, cortisol, in children. Following a repeated-measures crossover design, 40 children aged 9-14 years randomly consumed 1 of 5 isoenergetic (180 kcal) snacks per study session. These snacks included solid (potato chips, cookies, and cheese), semi-solid (Greek yogurt), and fluid (2% fat milk) snacks. FI was measured 120 min after snack consumption. Subjective appetite was measured at 0 (immediately before the snack), 15, 30, 45, 60, 90, and 120 min. Salivary cortisol (n = 18) was measured after the Greek yogurt and cookie snacks at 0, 30, 60, 90, and 120 min. FI did not differ between snacks (P = 0.15). The Greek yogurt (P < 0.0001) and cheese (P = 0.0009) snacks reduced average appetite compared with the 2% fat milk snack. Salivary cortisol levels were not affected by snack (P = 0.84). This study demonstrates that dairy snacks are as effective as other popular snacks at influencing subsequent FI. However, solid and semi-solid dairy snacks are more effective at repressing subjective appetite than a fluid dairy snack. Registered at ClinicalTrials.gov (NCT02484625). Novelty: Milk, Greek yogurt and cheese have a similar effect on short-term food intake in children as popular potato chips and cookie snacks. Solid, semi-solid and liquid snacks have a similar effect on short-term food intake in children.

Exogenous Ketones Lower Post-exercise Acyl-Ghrelin and GLP-1 but Do Not Impact Ad libitum Energy Intake

Ketosis and exercise are both associated with alterations in perceived appetite and modification of appetite-regulating hormones. This study utilized a ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE) to examine the impact of elevated ketone body D-β-hydroxybutyrate (βHB) during and after a bout of exercise on appetite-related hormones, appetite perception, and ad libitum energy intake over a 2 h post-exercise period. In a randomized crossover trial, 13 healthy males and females (age: 23.6 ± 2.4 years; body mass index: 25.7 ± 3.2 kg·m⁻²) completed an exercise session @ 70% VO_2peak for 60 min on a cycling ergometer and consumed either: (1) Ketone monoester (KET) (0.5 g·kg⁻¹ pre-exercise + 0.25 g·kg⁻¹ post-exercise); or (2) isocaloric dextrose control (DEX). Transient ketonaemia was achieved with βHB concentrations reaching 5.0 mM (range 4.1–6.1 mM) during the post-exercise period. Relative to the dextrose condition, acyl-ghrelin (P = 0.002) and glucagon-like peptide-1 (P = 0.038) were both reduced by acute ketosis immediately following exercise. AUC for acyl-ghrelin was lower in KET compared to DEX (P = 0.001), however there were no differences in AUC for GLP-1 (P = 0.221) or PYY (P = 0.654). Perceived appetite (hunger, P = 0.388; satisfaction, P = 0.082; prospective food consumption, P = 0.254; fullness, P = 0.282) and 2 h post-exercise ad libitum energy intake (P = 0.488) were not altered by exogenous ketosis. Although KE modifies homeostatic regulators of appetite, it does not appear that KE acutely alters energy intake during the post-exercise period in healthy adults.

Effect of Increasing the Dietary Protein Content of Breakfast on Subjective Appetite, Short-Term Food Intake and Diet-Induced Thermogenesis in Children

Dietary protein affects energy balance by decreasing food intake (FI) and increasing energy expenditure through diet-induced thermogenesis (DIT) in adults. Our objective was to investigate the effects of increasing the dietary protein in an isocaloric breakfast on subjective appetite, FI, blood glucose, and DIT in 9-14 y children. Two randomized repeated measures designs were used. In experiment 1, 17 children (9 boys, 8 girls) consumed isocaloric meals (450 kcal) on four separate mornings containing: 7 g (control), 15 g (low protein, LP), 30 g (medium protein, MP) or 45 g (high protein, HP) of protein. Blood glucose and subjective appetite were measured at baseline and regular intervals for 4 h, and FI was measured at 4 h. In experiment 2, 9 children (6 boys, 3 girls) consumed the control or HP breakfast on two separate mornings, and both DIT and subjective appetite were determined over 5 h. In experiment 1, all dietary protein treatments suppressed subjective appetite compared to control (p < 0.001), and the HP breakfast suppressed FI compared with the LP breakfast and control (p < 0.05). In experiment 2, DIT was higher after HP than control (p < 0.05). In conclusion, increasing the dietary protein content of breakfast had favorable effects on satiety, FI, and DIT in children.

Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males

OBJECTIVE

Chronic testosterone blood concentrations associate with food intake (FI), but acute effects of testosterone on appetite and effect of protein and glucose consumption on testosterone response have had little examination.

METHODS

In a randomized, crossover study, twenty-three adolescent (12-18 years old) males were given beverages containing either: (a) whey protein (1 g/kg body weight), (b) glucose (1 g/kg body weight) or (c) a calorie-free control (C). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. FI at an ad libitum pizza meal was assessed at 85 minutes.

RESULTS

Testosterone decreased acutely to 20 minutes after both protein and glucose with the decrease continuing after protein but not glucose to 65 minutes (P = 0.0382). LH was also decreased by both protein and glucose, but glucose had no effect at 20 minutes in contrast to protein (P < 0.001). Plasma testosterone concentration correlated positively with LH (r = 0.58762, P < 0.0001) and negatively with GLP-1 (r = -0.50656, P = 0.0003). No associations with appetite, ghrelin or glycaemic markers were found. Food intake was not affected by treatments.

CONCLUSION

Protein or glucose ingestion results in acute decreases in both plasma testosterone and LH in adolescent males. The physiological significance of this response remains to be determined as no support for testosterone's role in acute regulation of food intake was found.

Effect of dairy and nondairy snacks on postprandial blood glucose regulation in 9-14-year-old children

In adults, dairy consumption improves short-term blood glucose regulation. It is unknown if these short-term benefits extend to children of different weight statuses. The objective of this study was to investigate the effect of a dairy and nondairy snack in both normal-weight (NW) and overweight/obese (OW/OB) children on blood glucose regulation and food intake (FI). In a repeated-measures crossover design, 11 NW and 7 OW/OB children (age: 9-14 years), consumed, in random order, a dairy (Greek yogurt, 198.9 g, 171 kcal, 0 g fat, 17 g protein) or nondairy (mini sandwich-type cookies, 37.5 g, 175 kcal, 7.5 g fat, 1.3 g protein) snack containing 25 g of available carbohydrates. Ad libitum FI was measured 120 min after snack consumption. Blood glucose, insulin, C-peptide, and glucagon-like peptide-1 (GLP-1) were measured at 0 min (before the snack), and at 30, 60, 90, and 120 min after snack consumption. Insulin secretion was calculated from deconvolution of C-peptide. Hepatic insulin extraction was calculated as C-peptide divided by insulin. FI did not differ between snacks (P = 0.55). Mean blood glucose was lower (P < 0.001) and insulin higher (P < 0.0001) in the 120 min after consuming the dairy snack. C-Peptide concentrations (P = 0.75) and insulin secretion (P = 0.37) were not different between snacks. The increase in insulin was explained by reduced hepatic insulin extraction (P < 0.01). Consumption of the dairy snack also increased mean GLP-1 concentrations (P < 0.001). In conclusion, consumption of a dairy snack by NW and OW/OB children results in reduced postprandial blood glucose concentrations and elevated circulating insulin compared with a nondairy snack possibly because of delayed hepatic insulin extraction.

Effect of Commercially Available Sugar-Sweetened Beverages on Subjective Appetite and Short-Term Food Intake in Boys

It is unclear whether sugar sweetened beverages bypass regulatory controls of food intake (FI) in boys. The objective of the present study was to determine the effects of isovolumetric preloads (350 mL) of a fruit-flavoured drink (154 kcal), cola (158 kcal), 1% M.F. chocolate milk (224 kcal), and water (0 kcal) on subjective appetite and FI in boys aged 9–14 years. On four separate mornings, boys consumed one of the preloads in a random order; subjective appetite was measured at 15 min intervals, and FI was measured via an ad libitum pizza lunch at 60 min post-beverage consumption. In the 32 boys (age: 11.8 ± 0.3 years), FI was reduced (p < 0.001) after cola (940 ± 46 kcal) and chocolate milk (878 ± 41 kcal) compared with the water control (1048 ± 35 kcal) and after chocolate milk compared to the fruit drink (1005 ± 44 kcal). Cumulative FI after the fruit drink was greater than the water control (1159 ± 44 vs. 1048 ± 35 kcal; p = 0.03). Average appetite was not affected by the treatment, but the cola treatment resulted in greater fullness (p = 0.04) and lower prospective food consumption (p = 0.004) compared with the fruit drink. In conclusion, chocolate milk and cola suppressed next-meal FI at 60 min, while fruit drink increased cumulative FI (beverage + next meal) over 60 min in boys. Results from this study suggest that beverage composition is an important determinant of FI suppression in boys.

Effect of video game playing and a glucose preload on subjective appetite, subjective emotions, and food intake in overweight and obese boys

Video game playing (VGP) is associated with overweight/obesity (OW/OB). VGP and caloric preloads in the pre-meal environment influence short-term food intake (FI) in healthy-weight children. Therefore, the purpose of the present study was to examine the effect of pre-meal VGP and a glucose preload on subjective emotions, subjective appetite, and FI in boys with OW/OB. On 4 separate mornings, boys with OW/OB (n = 22; mean ± SD: age = 11.9 ± 1.6 years; body mass index percentile = 94.3 ± 3.9) participated in 4 test conditions. Two hours after a standardized breakfast, boys consumed equally sweetened preloads (250 mL) of sucralose (0 kcal) or glucose (200 kcal), with or without 30 min of subsequent VGP. Immediately after each test condition, FI was evaluated during an ad libitum pizza meal. Subjective appetite was measured at 0 (baseline), 15, and 30 min. Subjective emotions (aggression, anger, excitement, disappointment, happiness, upset, and frustration) were measured at 0 and 30 min. VGP did not affect FI, but the glucose preload decreased FI compared with the sucralose control (Δ = -103 ± 48 kcal, p < 0.01). However, cumulative FI (preload kcal + meal kcal) was 9% higher after the glucose preload (p < 0.01). Subjective appetite increased with time (p < 0.05) but was not influenced by preload or VGP. Frustration was the only subjective emotion that increased following VGP (p < 0.01). A glucose preload, but not VGP, suppressed FI in boys with OW/OB, suggesting a primary role of physiological factors in short-term FI regulation.

Effect of Commercially Available Sugar-Sweetened Beverages on Subjective Appetite and Short-Term Food Intake in Girls

Background: The effect of sugar-sweetened beverages (SSBs) on satiety and short-term food intake (FI) regulation in girls has received little attention. The objective of the present study was to compare the effect of pre-meal consumption of commercially available SSBs on subjective appetite and short-term FI in 9–14-year-old girls. The methods we used include using a randomized crossover design in which 28 girls consumed isovolumetric amounts (350 mL) of a fruit drink (154 kcal), cola (158 kcal), 1% chocolate milk (224 kcal), or water (control; 0 kcal) on four separate mornings. Subjective appetite and thirst were measured at regular intervals via visual analogue scales (VAS) and FI was assessed at 60 min post-beverage consumption. The results show that subjective appetite and thirst decreased after all beverages, but did not differ among beverages. Short-term FI was suppressed following consumption of chocolate milk (15%; p < 0.001) and cola (11%; p = 0.02) compared to the water control. However, cumulative energy intake (beverage (kcal) + test meal (kcal)) was not affected by beverage type. In conclusion, chocolate milk and cola, but not fruit drink, suppressed FI in girls while cumulative FI did not differ among treatments.

Body composition estimation in children and adolescents by bioelectrical impedance analysis: A systematic review

BACKGROUND

Bioelectrical impedance analysis (BIA) has commonly been used to assess the body composition of children and adolescents. BIA validation studies have found distinct correlation values with reference methods.

OBJECTIVES

To assess the reproducibility, correlation and mean differences in body composition estimated by BIA and reference methods, we systematically reviewed the literature in the pediatric population.

METHOD

The search for articles was conducted in March 2016 and was limited to articles published from 2005 to 2015 in the PubMed, Embase, EBSCO, Web of Science, Scopus and SciELO databases. Two reviewers independently performed data selection and extraction of studies that investigated the BIA validity, responsiveness, reliability and/or measurement error (reproducibility) to estimate body composition in children and adolescents with an average age ≤ 18 years.

RESULTS

The search produced 48 articles. Almost perfect reproducibility was found in the body fat percentage estimated by BIA, and there was almost perfect correlation between the BIA ratings and reference methods for fat mass and fat-free mass. Regarding component estimates, BIA underestimated the fat mass in both sexes.

CONCLUSIONS

The body fat percentage estimated by BIA exhibited almost perfect reproducibility. The fat mass and fat-free mass estimated by BIA correlated almost perfectly with the reference methods in both sexes. BIA underestimated the fat mass in both sexes.

Increased liver fat and glycogen stores after consumption of high versus low glycaemic index food: A randomized crossover study

AIM

To investigate the acute and longer-term effects of low (LGI) versus high glycaemic index (HGI) diets on hepatic fat and glycogen accumulation and related blood measures in healthy volunteers.

METHODS

Eight healthy men (age 20.1 ± 0.4 years, body mass index 23.0 ± 0.9 kg/m² ) attended a test day before and after a 7-day macronutrient- and energy-matched HGI or LGI diet, followed by a minimum 4-week wash-out period, and then returned to repeat the intervention with the alternative diet. During test days, participants consumed either an HGI or an LGI test meal corresponding to their diet week, and liver fat [ ¹ H magnetic resonance spectroscopy (MRS)], glycogen ( ¹³ C MRS) and gastric content volume (MRI) were measured. Blood samples were obtained regularly throughout the test day to assess plasma glucose and insulin levels.

RESULTS

Plasma glucose and insulin peak values and area under the curve were significantly greater after the HGI test meal compared with the LGI test meal, as expected. Hepatic glycogen concentrations increased more after the HGI test meal ( P < .05) and peak levels were significantly greater after 7 days of HGI dietary intervention compared with those at the beginning of the intervention ( P < .05). Liver fat fractions increased significantly after the HGI dietary intervention compared with the LGI dietary intervention (two-way repeated-measures analysis of variance P ≤ .05).

CONCLUSIONS

Compared with an LGI diet, a 1-week HGI diet increased hepatic fat and glycogen stores. This may have important clinical relevance for dietary interventions in the prevention and management of non-alcoholic fatty liver disease.

Methodological Challenges in Studies Examining the Effects of Breakfast on Cognitive Performance and Appetite in Children and Adolescents

Breakfast is purported to confer a number of benefits on diet quality, health, appetite regulation, and cognitive performance. However, new evidence has challenged the long-held belief that breakfast is the most important meal of the day. This review aims to provide a comprehensive discussion of the key methodological challenges and considerations in studies assessing the effect of breakfast on cognitive performance and appetite control, along with recommendations for future research. This review focuses on the myriad challenges involved in studying children and adolescents specifically. Key methodological challenges and considerations include study design and location, sampling and sample section, choice of objective cognitive tests, choice of objective and subjective appetite measures, merits of providing a fixed breakfast compared with ad libitum, assessment and definition of habitual breakfast consumption, transparency of treatment condition, difficulty of isolating the direct effects of breakfast consumption, untangling acute and chronic effects, and influence of confounding variables. These methodological challenges have hampered a clear substantiation of the potential positive effects of breakfast on cognition and appetite control and contributed to the debate questioning the notion that breakfast is the most important meal of the day.

Pre-meal screen-time activities increase subjective emotions, but not food intake in young girls

PURPOSE

To determine the effect of pre-meal screen-time activities on subjective emotions, subjective appetite, and food intake (FI) in 9-14 year-old girls.

METHODS

In this clinical study, 31 girls completed four 45-min treatment conditions of television viewing (TVV), video game playing (VGP), a challenging computer task (CT), and sitting without screen exposure (control) in a randomized order. Each treatment condition was followed immediately by an ad libitum pizza lunch, and FI was calculated from the weight of the consumed pizza. Subjective appetite was assessed at baseline, 15, 30, and 45 min during the treatment condition, and upon trial completion at 75 min. Subjective emotions were assessed at baseline and at 45 min.

RESULTS

FI was not affected by screen type, but was positively correlated with body composition (fat mass [FM, kg], fat free mass [FFM, kg]) in all treatment conditions. Subjective appetite was not affected by screen type, but increased with time in all treatment conditions (p < 0.0001). Subjective emotions were affected by VGP only. Anger, excitement, frustration, and upset feelings were increased at 45 min following VGP. VGP led to increased frustration compared to control (p = 0.0003), CT (p = 0.007) and TVV (p = 0.0002).

CONCLUSION

Exposure to TVV or CT before eating did not affect subjective emotions, subjective appetite, or FI, and no difference was found between screen activities and the control condition for average appetite or FI. Despite a change in subjective emotions during the VGP condition, there was no increase in subjective appetite or subsequent FI. These findings suggest that physiologic signals of satiation and satiety are not overridden by environmental stimuli of pre-meal screen-time exposure among young girls. (Clinical trial number NCT01750177).

Post-exercise appetite was affected by fructose content but not glycemic index of pre-exercise meals

The purpose of this study was to investigate whether both glycemic index (GI) and breakfast fructose content affect appetite during the postprandial period and recovery period after 1 hr of brisk walking. Ten healthy young men (age: 21.7 ± 1.5 y, body mass index: 20.9 ± 1.1 kg∙m(-2), VO2max: 53.7 ± 3.7 mL∙kg(-1)∙min(-1)) completed 1 hr of brisk walking at 46% VO2max 2 hr after eating one of three isocaloric breakfasts: a low-GI breakfast not including fructose content (LGI), a low-GI breakfast including fructose beverage (LGIF) and a high-GI breakfast (HGI). All breakfasts provided 1.0 g∙kg(-1) body weight carbohydrates, and the calculated GI values for the three breakfasts were 41, 39, and 72, respectively. In the LGIF and HGI trials, approximately 25% of participants' energy was derived from either fructose or glucose beverage. Appetite scores were measured every 30 min during the 2-hr postprandial period and 1-hr recovery period. During the postprandial period, the incremental areas under the blood response curve values of glucose and insulin were higher in the HGI trial, compared with those in the LGI and LGIF trials. At 30 and 60 min during the recovery period, the appetite scores were lower in the LGIF trial than those in the LGI and HGI trials. No differences were observed between the LGI and HGI trials. Breakfast fructose content, rather than GI, seems to affect appetite during the recovery period after 1 hr of brisk walking.

Acute decrease in serum testosterone after a mixed glucose and protein beverage in obese peripubertal boys

BACKGROUND AND OBJECTIVES

Delayed puberty and lower levels of testosterone (T) have been observed in adult obese males and some adolescent males. In adult men, enteral glucose ingestion results in acute lowering of serum testosterone levels; however, this has not been studied in adolescents. We aimed to examine the acute effect of a glucose/protein beverage on serum T concentration changes in obese peripubertal males. A second objective was to determine whether change in T concentration was related to appetite hormone levels.

PATIENTS AND METHODS

Twenty-three overweight and obese males aged 8-17 in pre-early (Tanner stage 1-2) and mid-late (Tanner stage 3-5) puberty were included in this cross-sectional study at the Clinical investigative unit at the Hospital for Sick Children. Participants consumed a beverage containing glucose and protein, and blood samples measuring pubertal hormones, ghrelin and glucagon-like peptide-1 (GLP-1) were taken over 60 min.

RESULTS

Across pubertal stages, there was a significant decrease in T levels in adolescent boys (-18·6 ± 3·1%, P < 0·01) with no proportional differences between pre-early and mid-late puberty (P = 0·09). Decrease in T was associated with a decrease in LH (r = 0·52, P = 0·02), and fasting T was inversely correlated with fasting ghrelin (r = -0·51, P = 0·03) with no correlation with GLP-1.

CONCLUSIONS

Intake of a mixed glucose/protein beverage acutely decreases T levels in overweight and obese peripubertal boys. A potential mechanism for this decrease may be secondary to an acute decrease in LH, but this requires further evaluation.

Acute changes in substrate oxidation do not affect short-term food intake in healthy boys and men

The acute relationship between substrate oxidation as measured by respiratory exchange ratio (RER) and food intake (FI) has not been defined. The purpose of the study was to determine acute relationships between RER, modified by exercise and a glucose load, and FI and net energy balance (NEB) in physically active normal-weight boys and men. In a crossover design, 15 boys (aged 9-12 years) and 15 men (aged 20-30 years) were randomly assigned to 4 conditions: (i) water and rest, (ii) glucose-drink and rest, (iii) water and exercise, and (iv) glucose-drink and exercise. Indirect calorimetry was used to determine RER, energy expenditure, and carbohydrate and fat oxidation. Subjective appetite and blood glucose were also measured. RER was higher after glucose (0.91 ± 0.01) compared with water (0.87 ± 0.01) (p < 0.0001), and after exercise (0.91 ± 0.01) compared with rest (0.88 ± 0.01) (p = 0.0043) in men (0.91 ± 0.01) compared with boys (0.88 ± 0.01) (p = 0.0002). FI (kcal·m(-2)) did not differ between boys and men. Glucose (582 ± 24 kcal·m(-2)) reduced FI compared with water (689 ± 25 kcal·m(-2)) (p < 0.0001), and further decreased FI when combined with exercise (554 ± 34 kcal·m(-2)) (p = 0.0303). NEB was reduced with exercise (573 ± 25 kcal·m(-2)) compared with the sedentary condition (686 ± 24 kcal·m(-2)) (p < 0.0001), but was higher after the glucose drink (654 ± 27 kcal·m(-2)) compared with water (605 ± 25 kcal·m(-2)) (p = 0.0267). No correlations were found between RER and FI or NEB in boys and men, except in the control condition of resting with water. In conclusion, the short-term modification of substrate oxidation by glucose and/or exercise in normal weight and active boys and men did not affect FI and NEB.

Mealtime exposure to food advertisements while watching television increases food intake in overweight and obese girls but has a paradoxical effect in boys

Food advertisements (ads) in TV programs influence food choice and have been associated with higher energy intake from snacks in children; however, their effects at mealtime have not been reported. Therefore, we measured energy intake at a pizza meal consumed by normal weight (NW) and overweight/obese (OW/OB) children (aged 9-14 years) while they watched a TV program with or without food ads and following pre-meal consumption of a sweetened beverage with or without calories. NW and OW/OB boys (experiment 1, n = 27) and girls (experiment 2, n = 23) were randomly assigned to consume equally sweetened drinks containing glucose (1.0 g/kg body weight) or sucralose (control). Food intake was measured 30 min later while children watched a program containing food or nonfood ads. Appetite was measured before (0-30 min) and after (60 min) the meal. Both boys and girls reduced energy intake at the meal in compensation for energy in the glucose beverage (p < 0.05). Food ads resulted in further compensation (51%) in boys but not in girls. Food ads increased energy intake at the meal (9%; p = 0.03) in OW/OB girls only. In conclusion, the effects of TV programs with food ads on mealtime energy intake and response to pre-meal energy consumption in children differ by sex and body mass index.

An after-school snack of raisins lowers cumulative food intake in young children

Snacks are an important part of children's dietary intake, but the role of dried fruit on energy intake in children is unknown. Therefore, the effect of ad libitum consumption of an after-school snack of raisins, grapes, potato chips, and chocolate chip cookies on appetite and energy intake in twenty-six 8- to 11-y-old normal-weight (15th to 85th percentile) children was examined. On 4 separate weekdays, 1 wk apart, children (11 M, 15 F) were given a standardized breakfast, morning snack (apple), and a standardized lunch. After school, children randomly received 1 of 4 ad libitum snacks and were instructed to eat until "comfortably full." Appetite was measured before and 15, 30, and 45 min after snack consumption. Children consumed the least calories from raisins and grapes and the most from cookies (P < 0.001). However, weight of raisins consumed was similar to potato chips (about 75 g) and lower compared to grapes and cookies (P < 0.009). Raisins and grapes led to lower cumulative food intake (breakfast + morning snack + lunch + after-school snack) (P < 0.001), while the cookies increased cumulative food intake (P < 0.001) compared to the other snacks. Grapes lowered appetite compared to all other snacks (P < 0.001) when expressed as a change in appetite per kilocalorie of the snack. Ad libitum consumption of raisins has potential as an after-school snack to achieve low snack intake prior to dinner, similar to grapes, compared to potato chips, and cookies in children 8 to 11 y old.

A premeal snack of raisins decreases mealtime food intake more than grapes in young children

The effect of a premeal snack of grapes, raisins, or a mix of almonds and raisins, compared with a water control, on food intake (FI) was examined in 8- to 11-year-old normal-weight (15th to 85th percentile) children. Children randomly received 1 of 4 ad libitum (Experiment 1: 13 boys, 13 girls) or fixed-calorie (150 kcal; Experiment 2: 13 boys, 13 girls) treatments, followed by an ad libitum pizza meal 30 min later. Appetite was measured throughout the study, and FI was measured at 30 min. The ad libitum consumption (Experiment 1) of raisins reduced pizza intake (p < 0.037), compared with water (26%), grapes (22%), and the mixed snack (15%). Cumulative energy intake (in kcal: snack + pizza) was lower after water and raisins than after either grapes or the mixed snack (p < 0.031). As a fixed-calorie (150 kcal) snack (Experiment 2), raisins reduced pizza intake, compared with water (∼11%, p = 0.005), and resulted in a cumulative intake similar to water; however, both grapes and the mixed snack resulted in higher cumulative intakes (p < 0.015). Appetite was lower after all caloric ad libitum snacks (p < 0.003) and after fixed amounts of grapes and the mixed snack (p < 0.037), compared with water. In conclusion, consumption of a premeal snack of raisins, but not grapes or a mix of raisins and almonds, reduces meal-time energy intake and does not lead to increased cumulative energy intake in children.

The effect of yellow pea protein and fibre on short-term food intake, subjective appetite and glycaemic response in healthy young men

Pulses are low-glycaemic foods rich in protein (20-25 %), resistant starch and fibre that suppress appetite and glycaemia. The objective of the present study was to elucidate the component(s) of yellow peas responsible for these benefits and assess their efficacy as value-added food ingredients. We investigated the effects of 10 or 20 g of isolated yellow pea protein (P10 and P20) or fibre (F10 and F20) on food intake (FI) at an ad libitum pizza meal served at 30 min (Expt 1, n 19) or 120 min (Expt 2, n 20) and blood glucose (BG) and appetite in young, healthy males (20-30 years). In Expt 1, P20 led to lower FI than control (4937 (sem 502) v. 5632 (sem 464) kJ (1180 (sem 120) v. 1346 (sem 111) kcal)) and all other treatments (P < 0·01) and lower cumulative FI (pizza meal kcal+treatment kcal; CFI) compared to F10 (5460 (sem 498) v. 6084 (sem 452) kJ (1305 (sem 119) v. 1454 (sem 108) kcal); P = 0·033). Both protein treatments suppressed mean pre-meal (0-30 min) BG compared to control (P < 0·05), whereas only P20 suppressed mean post-meal (50-120 min) BG (P < 0·01). There was no effect of treatment on pre-meal or post-meal appetite. In Expt 2, there was no effect of treatment on FI, CFI, or pre- or post-meal BG or appetite. In conclusion, protein is the component responsible for the short-term effects of yellow peas in the regulation of glycaemia and FI, but its second-meal effects disappear by 2 h post-consumption.

Overweight and obese boys reduce food intake in response to a glucose drink but fail to increase intake in response to exercise of short duration

The effect of short duration exercise (EXR) on food intake (FI) and energy balance (EB) is not well understood in either normal weight (NW) or overweight (OW) and obese (OB) 9-14 years old children. Our purpose was to describe the effects of activity and a glucose drink on short term FI, appetite, and EB in NW, OW, and OB boys. Each boy received in random order either a noncaloric Sucralose sweetened control or glucose (1.0 g·kg(-1) body weight) drink 5 min after either exercise (EXR) or sedentary (SED) activity. Boys exercised for 15 min at their ventilation threshold (V(T)) in experiment 1 or at 25% above their V(T) in experiment 2. FI was measured at an ad libitum pizza meal 30 min after drink consumption. FI was lower after the glucose drink (p < 0.001) but not affected by activity, even though EXR increased appetite (p < 0.001). OW/OB boys ate more total food than NW boys (p = 0.020). EB over the duration of the experiments was reduced by EXR in OW/OB boys (p = 0.013) but not in NW boys in either experiment (p > 0.05). We conclude that intake regulation in OW/OB boys in response to a glucose drink is similar to NW boys, but it may be less responsive to activity.

Television viewing at mealtime reduces caloric compensation in peripubertal, but not postpubertal, girls

The effect of television viewing (TVV) and pubertal status of 9- to 14-y-old girls on mealtime food intake (FI) after a premeal glucose drink was determined. On four separate mornings, girls randomly received equally sweetened drinks containing Sucralose (control) or glucose (1.0 g/kg body weight) in 250 mL of water 2 h after a standardized breakfast. FI from an ad libitum pizza meal was measured 30 min later with or without TVV. Appetite was measured at 15 min intervals to lunch and postmeal. TVV at mealtime had no effect on FI, however, glucose suppressed FI more with no TVV compared with TVV (24 versus 10%, p < 0.001), primarily because of its effect in peripubertal girls (p < 0.028). In postpubertal girls (n = 8), glucose reduced FI by ~27% in both the no TVV and TVV conditions, but in peripubertal girls (n = 17), reduction in FI was 22% without TVV and only 1% while TVV. Appetite correlated with FI at 30 min only in postpubertal girls. TVV at mealtime reduced caloric compensation after consumption of the glucose drink in peripubertal, but not postpubertal, girls, with no effect on mealtime FI. (Clinical trial number NCT01025687.)

The effect of duration of exercise at the ventilation threshold on subjective appetite and short-term food intake in 9 to 14 year old boys and girls

Background

The effect of exercise on subjective appetite and short-term food intake has received little investigation in children. Despite a lack of reported evaluation of short-duration activity programs, they are currently being implemented in schools as a means to benefit energy balance. The purpose of this study was to determine the effect of duration of exercise at the ventilation threshold (VeT) on subjective appetite and short-term food intake in normal weight boys and girls aged 9 to 14 years.

Methods

On 4 separate mornings and in random order, boys (n = 14) and girls (n = 15) completed 2 rest or 2 exercise treatments for 15 (short-duration; SD) or 45 min (long-duration; LD) at their previously measured VeT, 2 h after a standardized breakfast. Subjective appetite was measured at regular intervals during the study sessions and food intake from a pizza meal was measured 30 min after rest or exercise.

Results

An increase in average appetite, desire to eat, and hunger (p < 0.05) was attenuated by SD exercise, but was further increased (p < 0.05) by LD exercise. However, food intake after SD and LD exercise was similar to after rest in both boys and girls (p = 0.55). The energy cost of SD and LD exercise resulted in a lower net energy balance compared to resting during the study measurement period in boys (SD: Δ = -418 ± 301 kJ; LD: Δ = -928 ± 196 kJ) and in girls (SD: Δ = -297 ± 105 kJ; LD: Δ = -432 ± 115 kJ).

Conclusion

Neither SD nor LD exercise at the VeT increased short-term food intake and SD exercise attenuated increases in appetite. Thus, SD exercise programs in schools may be an effective strategy for maintaining healthier body weights in children.