Keeping a healthy body weight is an important part of healthy living. With more than 2/3 of the US adult population as either overweight or obese, how to lose weight is an ongoing interest for many.

 

    A few previously-shared strategies for weight management included breaking down meals into smaller ones or eating a specific type of food for promoting weight loss, such as avocado or soy. Here to share another strategy for those who want to lose weight: eat high-protein snacks.

 

    One study assessed the impact of daily consumption of a snack fortified with plant proteins on weight loss. The study included 70 overweight/obese adults without diabetes (26 male, 44 female). While following a 20% energy reduction for their diets, the study participants were randomized to either a control or an intervention group, consuming daily 70 g of conventional wheat biscuits or an isocaloric amount of wheat biscuits enriched with plant proteins originating from legumes and seeds, for a total of 12 weeks. The study participants were advised to consume 5 biscuits per day (1 biscuit = 14 g), as an afternoon snack (about 3 hours after lunch) during this 12-week study (1).

 

    By the end of the study, both study groups had decreases in body weight, body fat mass, and waist circumferences. Participants in the intervention group experienced greater weight loss (7.6 ± 2.7 vs. 6.2 ± 2.7%, p <0.05) and a marginally significant larger decrease in body fat mass (4.9 ± 2.2 vs. 3.9 ± 2.4 kg, p = 0.059). Greater reductions in caloric and carbohydrate intake and a trend towards a higher decrease in fat intake were also observed in participants of the intervention group (1).

 

    In this study, the plant protein flour that was enriched in the biscuit was from legumes. Legumes are an excellent dietary source of high-quality protein, a food with a low glycemic index, high in dietary fiber, low in fat, and free of saturated fat and cholesterol. The enriched biscuit had a higher amount of protein compared to the control biscuit (9.7 g and 5.1 g per daily snacking portion of 70 g, respectively). It also contained a higher amount of dietary fiber; however, the difference per serving (2.1 g per 70 g) was not significant enough to explain the superior results achieved by the subjects in the intervention group (1).

 

    The authors believed that the incorporation of plant-based proteins with high content of amino acids with appetite-regulating properties (particularly the branch-chain amino acid and arginine) in wheat biscuits might have contributed to the greater weight loss and improvement of metabolic parameters in subjects who were overweight or obese. The enriched biscuit was rich in L-arginine and branch-chain amino acid ( i.e. leucine), both are known to be associated with appetite regulation. High protein snacks eaten prior to dinner may improve appetite control and lead to lower caloric, carbohydrate, and fat consumption throughout the day, which contributed to a significantly higher decrease in caloric intake. Between the start to the end of the study, the control group reduced the caloric intake from 2529.2 ± 471.1 to 1917.3 ± 262.3 kcal (-612 kcal/day) while the intervention group reduced the caloric intake from 2463.3 ± 441.1 to 1736.2 ± 291.6 kcal (-727 kcal/day), a 115 kcal difference per day between the study groups (1).

 

    A similar impact of high-protein snacks on appetite and energy intake had been found in other studies. One study showed that the consumption of high-protein afternoon snacks improved appetite control, leading to a reduction of high-fat evening snacking compared to the consumption of snacks with lower protein content (2). In this study, 31 healthy adolescents consumed the following afternoon snacks (in randomized order) for 3 days: high-protein snack (26 g of protein/6 g of fat per 27 g of carbohydrates), high-fat snack (4 g of protein/12 g of fat per 32 g of carbohydrates), and no snack. On day 4 of each treatment, the participants completed an 8-hour testing day containing pre- and post-snack appetite questionnaires and eating initiation-related functional measurements. Ad libitum dinner and evening snacks were provided and assessed. The high-protein snack delayed eating initiation vs. no snack (p < 0.05). Both snacks reduced appetite vs. no snack (p < 0.001) with high-protein snacks eliciting greater reductions than a high-fat snack (p < 0.05) (2).

 

    Although no treatment differences in daily energy intake were detected, a high-protein snack led to greater protein consumption than no snack (p < 0.05) and greater protein and lower fat consumption than a high-fat snack (p < 0.05). High-protein snacks led to fewer high-fat/high-sugar evening snacks than no snacks (p < 0.01) and high-fat snacks (p = 0.09).  This study showed that afternoon snacking, particularly on high-protein soy foods, improved appetite, satiety, and diet quality in adolescents (2).

 

    Twenty-three women were randomized in a single-blind cross-over study with 2 interventions, a high-fat high sugar snack and a comparatively higher protein, higher-fiber snack intervention. Snacks were eaten at mid-morning and mid-afternoon, and a standard breakfast and ad libitum buffet lunch. The glucose and insulin responses over 9 hours were significantly lower (p<0.05) during the high protein snack intervention. Peak glucose levels were also 16% lower after the morning high protein snack (p <0.001). The morning high protein snack reduced the energy intake at the buffet lunch meal by 5% (p < 0.05). Altering the macronutrient composition of a snack can assist in reducing energy intake at a subsequent meal and improve short-term glucose and insulin profiles (3).

 

    Fifteen healthy women randomly consumed 160 kcal afternoon yogurt snacks containing low, moderate, or high protein (5, 14, and 24 g protein, respectively) or had no snack for 3 days. On day 4, the volunteers consumed a standardized lunch. The respective snack was eaten 3 hours post-lunch. Perceived sensations were measured every 30 minutes 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 was sustained up to 120 minutes post-snack vs. no snack (all, p<0.05). Between snacks, hunger was lower and fullness was higher throughout post-snack following high protein vs. low protein (p<0.05). Snacking delayed the onset of eating vs. no snack (p<0.05). Specifically, dinner was requested at 124 ± 7 minutes following no snack, 152 ± 7 minutes with Low protein, 158 ± 7 minutes following Moderate protein, and 178 ± 7 min post-snack for High protein. High protein led to the most delayed request time vs. low protein and moderate protein (p<0.05). The energy consumed at dinner was lower after yogurt snacks vs. no snacks. This study showed that an afternoon snack of yogurt, containing 24 g of protein, led to reduced hunger, increased fullness, and delayed subsequent eating compared to lower protein snacks in healthy women (4).

 

    The effects of soy-enriched high-protein snacks were investigated in women with normal-weight obesity. Normal-weight obesity is recognized as a specific type of obesity and characterizes individuals as having normal body mass and body mass index with an elevated fat mass (BMI <25 (kg/m2) and body fat percentage ˃ 30%) and concurrent diminished lean mass. One hundred and seven (107) women with normal weight obesity [(age: 24 ± 3 yrs, BMI: 22.7 ± 2.3 kg/m2, body fat percentage: 38 ± 3.2%)] who were assigned to one of two groups; high protein snack (n = 52) containing 50 g soybean or isocaloric low-protein snack (protein: 18.2 g, carbohydrate: 15 g, fat: 10 g, energy: 210 kcal) or isocaloric low protein snack (n=55) containing 3.5 servings of fruit (protein: <2 g, carbohydrate: ≈50 g, fat: <1 g, energy: ≈210 kcal) as part of their daily meals (as a snack at 10 a.m.). Appetite, energy intake (high protein snack  -166.2 kcal/day and low protein snack  91.3 kcal), carbohydrate intake (high protein snack  -58.4 g/day and low protein snack  6.4 g/day), waist circumference (high protein snack  -4.3 cm and low protein snack -0.9 cm), and body fat percentage (high protein snack -3.7% and low protein snack -0.9%) were significantly reduced (p < 0.05), while skeletal muscle mass (high protein snack 1.2 kg and low protein snack 0.3 kg) significantly increased in the high protein snack group compared to the low protein snack group, respectively. Six months of a soy-enriched high-protein snack replacement decreased appetite and improved body composition in women with normal-weight obesity (5).

 

    These study findings suggested that plant protein enriched high protein snacks, such as soy-enriched snacks or protein-added yogurt, have positive effects on appetite control, which can be an efficacious strategy for promoting weight loss and improving body composition. The take-home message for those who like to snack but also want to lose weight is to eat more high-protein snacks.

 

References:

1. Binou, P., Yanni, A. E., Kartsioti, K., Barmpagianni, A., Konstantopoulos, P., Karathanos, V. T., & Kokkinos, A. (2022). Wheat Biscuits Enriched with Plant-Based Protein Contribute to Weight Loss and Beneficial Metabolic Effects in Subjects with Overweight/Obesity. Nutrients, 14(12). doi:10.3390/nu14122516.

2. Leidy H.J., Todd C.B., Zino A.Z., Immel J.E., Mukherjea R., Shafer R.S., Ortinau L.C., Braun M. Consuming High-Protein Soy Snacks Affects Appetite Control, Satiety, and Diet Quality in Young People and Influences Select Aspects of Mood and Cognition. J. Nutr. 2015;145:1614–1622. doi: 10.3945/jn.115.212092.

3. Williams G., Noakes M., Keogh J., Foster P., Clifton P. High protein high fibre snack bars reduce food intake and improve short term glucose and insulin profiles compared with high fat snack bars. Asia Pac. J. Clin. Nutr. 2006;15:443–450.

4. Douglas S.M., Ortinau L.C., Hoertel H.A., Leidy H.J. Low, moderate, or high protein yogurt snacks on appetite control and subsequent eating in healthy women. Appetite. 2013;60:117–122. doi: 10.1016/j.appet.2012.09.012.

5. Haghighat N., Ashtary-Larky D., Bagheri R., Wong A., Cheraghloo N., Moradpour G., Nordvall M., Asbaghi O., Moeinvaziri N., Amini M., et al. Effects of 6 Months of Soy-Enriched High Protein Compared to Eucaloric Low Protein Snack Replacement on Appetite, Dietary Intake, and Body Composition in Normal-Weight Obese Women: A Randomized Controlled Trial. Nutrients. 2021;13:2266. doi: 10.3390/nu13072266.