A high-protein breakfast prevents body fat gain, through reductions in daily intake and hunger, in "Breakfast skipping" adolescents.

OBJECTIVE: The purpose of this study was to examine whether the daily consumption of normal-protein (NP) vs. high-protein (HP) breakfast meals improves appetite control, food intake, and body composition in "breakfast skipping" young people with overweight/obesity. METHODS: Fifty-seven adolescents (age: 19 ± 1 years; BMI: 29.7 ± 4.6 kg m(-2)) completed a 12-week randomized controlled trial in which the adolescents consumed either a 1,464 kJ NP breakfast (13 g protein) or a HP breakfast (35 g protein) or continued to skip breakfast (CON). Pre- and post-study appetite, food intake, body weight, and body composition were assessed. RESULTS: Time-by-group interactions (P < 0.05) were detected for body fat mass, daily intake, and perceived hunger. Specifically, HP prevented fat mass gains over the 12 weeks (-0.4 ± 0.5 kg) vs. CON (+1.6 ± 0.9 kg; P = 0.02), whereas NP did not (+0.3 ± 0.5 kg). HP led to reductions in daily intake (-1,724 ± 954 kJ) vs. CON (+1,556 ± 745 kJ; P = 0.03), whereas NP did not (+494 ± 213 kJ). Lastly, only the HP group experienced reductions in daily hunger vs. CON (P < 0.05). However, when directly comparing the HP vs. NP groups, no differences were detected in any outcomes. CONCLUSIONS: The daily addition of a HP breakfast improved indices of weight management as illustrated by the prevention of body fat gain, voluntary reductions in daily intake, and reductions in daily hunger in breakfast skipping adolescents with overweight/obesity.

Effects of high-protein vs. high- fat snacks on appetite control, satiety, and eating initiation in healthy women.

BACKGROUND: The purpose of this study was to determine whether a high-protein afternoon yogurt snack improves appetite control, satiety, and reduces subsequent food intake compared to other commonly-consumed, energy dense, high-fat snacks. FINDINGS: Twenty, healthy women (age: 27 ± 2 y; BMI: 23.4 ± 0.7 kg/m2) completed the randomized crossover design study which included 3, 8-h testing days comparing the following 160 kcal afternoon snacks: high-protein yogurt (14 g protein/25 g CHO/0 g fat); high-fat crackers (0 g protein/19 g CHO/9 g fat); and high-fat chocolate (2 g protein/19 g CHO/9 g fat). Participants were acclimated to each snack for 3 consecutive days. On day 4, the participants consumed a standardized breakfast and lunch; the respective snack was consumed 3-h post-lunch. Perceived hunger and fullness were assessed throughout the afternoon until dinner was voluntarily requested. An ad libitum dinner was then provided. The consumption of the yogurt snack led to greater reductions in afternoon hunger vs. chocolate (p < 0.01). No differences in afternoon fullness were detected. The yogurt snack also delayed eating initiation by approximately 30 min compared to the chocolate snack (p < 0.01) and approximately 20 min vs. crackers (p = 0.07). The yogurt snack led to approximately 100 fewer kcals consumed at dinner vs. the crackers (p = 0.08) and chocolate (p < 0.05). No other differences were detected. CONCLUSION: These data suggest that, when compared to high-fat snacks, eating less energy dense, high-protein snacks like yogurt improves appetite control, satiety, and reduces subsequent food intake in healthy women.

A randomized crossover, pilot study examining the effects of a normal protein vs. high protein breakfast on food cravings and reward signals in overweight/obese "breakfast skipping", late-adolescent girls.

BACKGROUND: This pilot study examined whether the addition of a normal protein (NP) vs. high protein (HP) breakfast leads to alterations in food cravings and plasma homovanillic acid (HVA), which is an index of central dopamine production, in overweight/obese 'breakfast skipping' late-adolescent young women. METHODS: A randomized crossover design was incorporated in which 20 girls (age 19 ± 1 y; BMI 28.6 ± 0.7 kg/m2) consumed 350 kcal NP (13 g protein) breakfast meals, 350 kcal HP (35 g protein) breakfast meals, or continued breakfast skipping (BS) for 6 consecutive days/pattern. On day 7 of each pattern, a 4 h testing day was completed including the consumption of breakfast (or no breakfast) followed by food craving questionnaires and blood sampling for HVA concentrations throughout the morning. RESULTS: Both breakfast meals reduced post-meal cravings for sweet and savory foods and increased HVA concentrations vs. BS (all, p < 0.05). Between breakfast meals, the HP breakfast tended to elicit greater reductions in post-meal savory cravings vs. NP (p = 0.08) and tended to elicit sustained increases in HVA concentrations prior to lunch vs. NP (p = 0.09). Lastly, HVA concentrations were positively correlated with the protein content at breakfast (r: 0.340; p < 0.03). CONCLUSIONS: Collectively, these findings suggest that the addition of breakfast reduces post-meal food cravings and increases homovanillic acid concentrations in overweight/obese young people with higher protein versions eliciting greater responses.

The effects of increased dietary protein yogurt snack in the afternoon on appetite control and eating initiation in healthy women.

BACKGROUND: A large portion of daily intake comes from snacking. One of the increasingly common, healthier snacks includes Greek-style yogurt, which is typically higher in protein than regular yogurt. This study evaluated whether a 160 kcal higher-protein (HP) Greek-style yogurt snack improves appetite control, satiety, and delays subsequent eating compared to an isocaloric normal protein (NP) regular yogurt in healthy women. This study also identified the factors that predict the onset of eating. FINDINGS: Thirty-two healthy women (age: 27 ± 2y; BMI: 23.0 ± 0.4 kg/m2) completed the acute, randomized crossover-design study. On separate days, participants came to our facility to consume a standardized lunch followed by the consumption of the NP (5.0 g protein) or HP (14.0 g protein) yogurt at 3 h post-lunch. Perceived hunger and fullness were assessed throughout the afternoon until dinner was voluntarily requested; ad libitum dinner was then provided. Snacking led to reductions in hunger and increases in fullness. No differences in post-snack perceived hunger or fullness were observed between the NP and HP yogurt snacks. Dinner was voluntarily requested at approximately 2:40 ± 0:05 h post-snack with no differences between the HP vs. NP yogurts. Ad libitum dinner intake was not different between the snacks (NP: 686 ± 33 kcal vs. HP: 709 ± 34 kcal; p = 0.324). In identifying key factors that predict eating initiation, perceived hunger, fullness, and habitual dinner time accounted for 30% of the variability of time to dinner request (r = 0.55; p < 0.001). CONCLUSIONS: The additional 9 g of protein contained in the high protein Greek yogurt was insufficient to elicit protein-related improvements in markers of energy intake regulation.

Beneficial effects of a higher-protein breakfast on the appetitive, hormonal, and neural signals controlling energy intake regulation in overweight/obese, "breakfast-skipping," late-adolescent girls.

BACKGROUND: Breakfast skipping is a common dietary habit practiced among adolescents and is strongly associated with obesity. OBJECTIVE: The objective was to examine whether a high-protein (HP) compared with a normal-protein (NP) breakfast leads to daily improvements in appetite, satiety, food motivation and reward, and evening snacking in overweight or obese breakfast-skipping girls. DESIGN: A randomized crossover design was incorporated in which 20 girls [mean ± SEM age: 19 ± 1 y; body mass index (in kg/m(2)): 28.6 ± 0.7] consumed 350-kcal NP (13 g protein) cereal-based breakfasts, consumed 350-kcal HP egg- and beef-rich (35 g protein) breakfasts, or continued breakfast skipping (BS) for 6 d. On day 7, a 10-h testing day was completed that included appetite and satiety questionnaires, blood sampling, predinner food cue-stimulated functional magnetic resonance imaging brain scans, ad libitum dinner, and evening snacking. RESULTS: The consumption of breakfast reduced daily hunger compared with BS with no differences between meals. Breakfast increased daily fullness compared with BS, with the HP breakfast eliciting greater increases than did the NP breakfast. HP, but not NP, reduced daily ghrelin and increased daily peptide YY concentrations compared with BS. Both meals reduced predinner amygdala, hippocampal, and midfrontal corticolimbic activation compared with BS. HP led to additional reductions in hippocampal and parahippocampal activation compared with NP. HP, but not NP, reduced evening snacking of high-fat foods compared with BS. CONCLUSIONS: Breakfast led to beneficial alterations in the appetitive, hormonal, and neural signals that control food intake regulation. Only the HP breakfast led to further alterations in these signals and reduced evening snacking compared with BS, although no differences in daily energy intake were observed. These data suggest that the addition of breakfast, particularly one rich in protein, might be a useful strategy to improve satiety, reduce food motivation and reward, and improve diet quality in overweight or obese teenage girls. This trial was registered at clinicaltrials.gov as NCT01192100.

Low, moderate, or high protein yogurt snacks on appetite control and subsequent eating in healthy women.

This study assessed whether afternoon snacks, varying in protein content, influence appetite-control and eating initiation. Fifteen healthy women (age: 26 ± 2 y) randomly consumed 160 kcal afternoon yogurt snacks containing Low (LP), Moderate (MP), or High (HP) protein (5,14,24 g protein, respectively) or had no snack (NS) for 3 days. On day 4, the volunteers came to our facility to consume a standardized lunch. The respective snack pattern was completed 3h post-lunch. Perceived sensations were measured every 30 min until dinner was voluntarily requested. An ad libitum dinner was then provided. Snacking, regardless of protein content, led to reduced hunger and increased fullness, which were sustained up to 120 min post-snack vs. NS (all, p<0.05). Between snacks, hunger was lower and fullness was higher throughout post-snack following HP vs. LP (p<0.05). Snacking delayed the onset of eating vs. NS (all, p<0.05). Specifically, dinner was requested at 124 ± 7 min following NS, 152 ± 7 min with LP, 158 ± 7 min following MP, and 178 ± 7 min post-snack for HP. Between snacks, HP led to the latest request time vs. LP (p<0.001) and MP (p<0.05). Although the energy content consumed at dinner was lower following the yogurt snacks vs. NS, the 160 kcal snacks were not fully compensated for at this meal. In conclusion, an afternoon snack of Greek yogurt, containing 24 g protein, led to reduced hunger, increased fullness, and delayed subsequent eating compared to lower protein snacks in healthy women.