Predictors of Post-Exercise Energy Intake in Adolescents Ranging in Weight Status from Overweight to Severe Obesity

Exercise may sensitize individuals with overweight and obesity to appetitive signals (e.g., hunger and fullness cues), overriding trait eating behaviors that contribute to overeating and obesity, such as uncontrolled eating. The objective of the current study was to measure predictors of objective ad libitum energy intake at a laboratory-based, post-exercise test-meal in adolescents ranging in weight status from overweight to severe obesity. We hypothesized that appetitive states, rather than appetitive traits, would be the strongest predictors of energy intake at a post-exercise test-meal, after controlling for body size. At Baseline, 30 adolescents (ages 10–16 years, 50% female (F), 43% non-Hispanic white (NHW), 83% with obesity (OB)) completed state and trait appetite measures and an ad libitum dinner meal following intensive exercise. Nineteen of those participants (47% F, 32% NHW, 79% OB) completed identical assessments two years later (Year 2). Energy intake (kcal) at each time point was adjusted for fat-free mass index (i.e., body size). Adjusted energy intake was reliable from Baseline to Year 2 (ICC = 0.84). Multiple pre-meal appetite ratings were associated with test-meal energy intake. In stepwise linear regression models, pre-meal prospective food consumption was the strongest and only significant predictor of test-meal energy intake at both Baseline (R2 = 0.25, p = 0.005) and Year 2 (R2 = 0.41, p = 0.003). Baseline post-exercise energy intake was associated with weight change over two years (R2 = 0.24, p = 0.04), but not with change in fat mass (p = 0.11). Appetitive traits were not associated with weight or body composition change (p > 0.22). State appetite cues were the strongest predictors of post-exercise energy intake, independent of body size. Future studies should examine whether long-term exercise programs enhance responsiveness to homeostatic appetite signals in youth with overweight and obesity, with a goal to reduce excess energy intake and risk for weight gain over time.

Whey- and Soy Protein Isolates Added to a Carrot-Tomato Juice Alter Carotenoid Bioavailability in Healthy Adults

Recent findings suggested that proteins can differentially affect carotenoid bioaccessibility during gastro-intestinal digestion. In this crossover, randomized human trial, we aimed to confirm that proteins, specifically whey- and soy-protein isolates (WPI/SPI) impact postprandial carotenoid bioavailability. Healthy adults (n = 12 males, n = 12 females) were recruited. After 2-week washout periods, 350 g of a tomato-carrot juice mixture was served in the absence/presence of WPI or SPI (50% of the recommended dietary allowance, RDA ≈ 60 g/d). Absorption kinetics of carotenoids and triacylglycerols (TAGs) were evaluated via the triacylglycerol-rich lipoprotein (TRL) fraction response, at timed intervals up to 10 h after test meal intake, on three occasions separated by 1 week. Maximum TRL-carotenoid concentration (Cmax) and corresponding time (Tmax) were also determined. Considering both genders and carotenoids/TAGs combined, the estimated area under the curve (AUC) for WPI increased by 45% vs. the control (p = 0.018), to 92.0 ± 1.7 nmol × h/L and by 57% vs. SPI (p = 0.006). Test meal effect was significant in males (p = 0.036), but not in females (p = 0.189). In males, significant differences were found for phytoene (p = 0.026), phytofluene (p = 0.004), α-carotene (p = 0.034), and β-carotene (p = 0.031). Cmax for total carotenoids (nmol/L ± SD) was positively influenced by WPI (135.4 ± 38.0), while significantly lowered by SPI (89.6 ± 17.3 nmol/L) vs. the control (119.6 ± 30.9, p < 0.001). Tmax did not change. The results suggest that a well-digestible protein could enhance carotenoid bioavailability, whereas the less digestible SPI results in negative effects. This is, to our knowledge, the first study finding effects of proteins on carotenoid absorption in humans.

Effects of β-glucan and inulin consumption on postprandial appetite, energy intake and food consumption in healthy females: A randomized controlled trial

Background: To date, several researchers have investigated the association between dietary fibre consumption and satiety. However, there is no study that includes both inulin and β-glucan to compare energy intake (EI) and satiety ratings. Aim: The current study investigated the effects of two dietary fibres, β-glucan and inulin, on satiety and food intake. Methods: The study was carried out among 24 woman over 18 years of age. The dietary fibres β-glucan (6 g/day) or inulin (6 g/day) were consumed by participants for five weeks. On the first and fifth week visits, the participants consumed a standard breakfast followed by an ad libitum test meal. Appetite was assessed using visual analogue scales (VAS) before and after breakfast. EI was measured at the test meal using plate waste. Results: Both dietary fibres significantly reduced the VAS scores of hunger, prospective food consumption and desire to eat, and increased satiety compared with the control group. However, the area under curve data for the VAS scores did not exhibit a significant difference. Significant reductions in EI and anthropometric values between the first and fifth week measures were observed in both dietary fibre groups. Statistically significant changes occurred in the body weight [-1.25 (1.27) kg], body mass index [-0.41 (0.42) kg/m2], waist circumference [-1.25 (1.04) cm] and waist/hip ratio [-0.01(0.01)] in the β-glucan group, whereas a statistically significant change occurred in body fat percentage in the inulin group [-2.16% (7.49)]. Conclusions: Overall, these findings demonstrate that the participants consuming β-glucan over the course of the five weeks had less EI, felt less hunger and had more satiety.

The Role of Ultrasonography in the Diagnosis of Functional Dyspepsia

Background: Functional dyspepsia (FD) is a syndrome mostly diagnosed by subjective patients’ symptoms after excluding organic, systemic and metabolic diseases. Aim: The goal of this study is to evaluate gastric emptying in patients with functional dyspepsia, by measuring the antral area (cm2) after the intake of a test meal using ultrasonography as an objective and widely applicable method. Material and Methods: This study included 30 patients (mean age of 46.53 ±9.73 years) with symptoms of FD according to the ROMA IV criteria and 30 healthy individuals (mean age of 42.87 ±4.42 years). A 5 MHz ultrasound probe was used to measure the stomach antral area at 6 different time points: in the fasting state, following the meal intake at 5, 30, 60, 90 and 120 min postprandially. Results: The antral area was statistically significantly larger after a 30-minute postprandial period in patients with FD comparing to healthy controls (p<0.05). There was a statistically significant difference in the rate of gastric emptying at 120 minutes in patients with functional dyspepsia, compared to healthy subjects (p <0.01). Patients with postprandial distress syndrome had the average value of gastric emptying 48.25 compared to 56.09 in patients with epigastric pain syndrome (p <0.05). The slowest emptying was observed in patients with nausea and postprandial fullness (p <0.05). Conclusion: Functional dyspepsia is associated with delayed gastric emptying. Using ultrasonography to measure the antral area helps us to assess gastric emptying and therefore to assess patients with functional dyspepsia. The antral area was significantly larger in patients with functional dyspepsia compared to healthy subjects after the test meal, suggesting slower gastric emptying in the dyspeptic patients. Since the diagnosis of functional dyspepsia is based mostly on diverse patients’ symptoms, using ultrasonography to measure the antral area helps us to objectively assess this problem.

Iron Absorption from Iron-Biofortified Sweetpotato Is Higher Than Regular Sweetpotato in Malawian Women while Iron Absorption from Regular and Iron-Biofortified Potatoes Is High in Peruvian Women

ABSTRACT Background Sweetpotato and potato are fast-maturing staple crops and widely consumed in low- and middle-income countries. Conventional breeding to biofortify these crops with iron could improve iron intakes. To our knowledge, iron absorption from sweetpotato and potato has not been assessed. Objective The aim was to assess iron absorption from regular and iron-biofortified orange-fleshed sweetpotato in Malawi and yellow-fleshed potato and iron-biofortified purple-fleshed potato in Peru. Methods We conducted 2 randomized, multiple-meal studies in generally healthy, iron-depleted women of reproductive age. Malawian women (n = 24) received 400 g regular or biofortified sweetpotato test meals and Peruvian women (n = 35) received 500 g regular or biofortified potato test meals. Women consumed the meals at breakfast for 2 wk and were then crossed over to the other variety. We labeled the test meals with 57Fe or 58Fe and measured cumulative erythrocyte incorporation of the labels 14 d after completion of each test-meal sequence to calculate iron absorption. Iron absorption was compared by paired-sample t tests. Results The regular and biofortified orange-fleshed sweetpotato test meals contained 0.55 and 0.97 mg Fe/100 g. Geometric mean (95% CI) fractional iron absorption (FIA) was 5.82% (3.79%, 8.95%) and 6.02% (4.51%, 8.05%), respectively (P = 0.81), resulting in 1.9-fold higher total iron absorption (TIA) from biofortified sweetpotato (P &lt; 0.001). The regular and biofortified potato test meals contained 0.33 and 0.69 mg Fe/100 g. FIA was 28.4% (23.5%, 34.2%) from the regular yellow-fleshed and 13.3% (10.6%, 16.6%) from the biofortified purple-fleshed potato meals, respectively (P &lt; 0.001), resulting in no significant difference in TIA (P = 0.88). Conclusions FIA from regular yellow-fleshed potato was remarkably high, at 28%. Iron absorbed from both potato test meals covered 33% of the daily absorbed iron requirement for women of reproductive age, while the biofortified orange-fleshed sweetpotato test meal covered 18% of this requirement. High polyphenol concentrations were likely the major inhibitors of iron absorption. These trials were registered at www.clinicaltrials.gov as NCT03840031 (Malawi) and NCT04216030 (Peru).

Satiety, Taste and the Cephalic Phase: A Crossover Designed Pilot Study into Taste and Glucose Response

The glycemic response produced by a food depends on both the glycemic index of the food itself, and on how the body reacts to the food as it is consumed and digested, in turn dependent on sensory cues. Research suggests that taste stimulation can induce the cephalic phase insulin response before food has reached the digestion, priming the body for an incoming glucose load. This glycemic response can consequently affect the amount of food consumed in a subsequent meal. The aim of this study was to investigate the effects on satiety of four preloads that differed in caloric content and sensory properties, in a small group of female and male participants (n = 10). Water, sucrose, sucralose, and maltodextrin were used to represent 4 different conditions of the preload, with or without energy, and with or without sweet taste. Individual plasma glucose concentrations were sampled at baseline, 45 min after consuming the preload, and after consuming an ad-libitum test meal. Hunger, fullness, desire to eat, and thoughts of food feeling were assessed every 15 min using visual analog scales. Results in male participants when comparing two solutions of equal caloric content, maltodextrin and sucrose, showed that plasma glucose concentration spiked in the absence of taste input (p = 0.011). Maltodextrin, while providing calories does not have the sweet taste that can serve to trigger cephalic phase insulin release to attenuate an incoming glucose load, and was accompanied by significantly greater change in feelings of satiety than with the other preloads. Despite the difference in postprandial blood glucose, the energy consumed in the test meal across the treatments was not significantly different in either males or females. Results highlight the importance of taste in stimulating the body for the efficient and effective glucose homeostasis.

Development and validation of nutrient estimates based on a food-photographic record in Japan

Background Previous studies have reported that estimates of portion size, energy, and macronutrients such as carbohydrates, proteins, and fat based on the food-photographic record closely correlate with directly weighed values. However, the correlation based on a large sample of the test meal with the evidence of many nutrients is yet to be determined. We conducted this study to assess the correlation and difference between the food-photographic record and weighed results for 44 nutrients based on a larger number of test meals than those in previous studies. Methods We assessed the nutrients of test meals using a food-photographic record and direct weighing and compared the results of the two methods. Twenty participants prepared a total of 1163 test meals. Each participant cooked 28–29 different kinds of dishes. Five participants cooked the same dish with their own recipes. For the most commonly consumed 41 dishes, 20 participants served a meal with their usual portion size. For the remaining 73 dishes, five participants served a meal with their usual portion size. An independent researcher weighed each ingredient and calculated the nutrients of the test meals. The participants took photographs of the test meals using a digital camera. Two independent, trained analysts measured the longitudinal and transverse diameters of the food area on the photographs of the test meals, compared the portion size with the reference photographs, and calculated the nutrients based on a database that contained reference photographs. Results Rank correlation coefficients between estimates from the food-photographic record of each test meal and weighed results were high for portion size (r = 0.93), energy (r = 0.93), protein (r = 0.90), fat (r = 0.92), and carbohydrate (r = 0.94), and those for the 44 nutrients ranged from 0.78 to 0.94. We found high reproducibility between the two analysts for all the nutrients (r > 0.90). Conclusions We found a high correlation and small difference between the food-photographic record method and weighed results of a large number of nutrients in many test meals.