Background Low-calorie sweeteners (LCSs) provide sweetness with little or no energy. However, each LCS's unique chemical structure has potential to elicit different sensory, physiological, and behavioral responses that affect body weight. Objective The purpose of this trial was to compare the effects of consumption of 4 LCSs and sucrose on body weight, ingestive behaviors, and glucose tolerance over a 12-wk intervention in adults (18–60 y old) with overweight or obesity (body mass index 25–40 kg/m2). Methods In a parallel-arm design, 154 participants were randomly assigned to consume 1.25–1.75 L of beverage sweetened with sucrose (n = 39), aspartame (n = 30), saccharin (n = 29), sucralose (n = 28), or rebaudioside A (rebA) (n = 28) daily for 12 wk. The beverages contained 400–560 kcal/d (sucrose treatments) or <5 kcal/d (LCS treatments). Anthropometric indexes, energy intake, energy expenditure, appetite, and glucose tolerance were measured at baseline. Body weight was measured every 2 wk with energy intake, expenditure, and appetite assessed every 4 wk. Twenty-four-hour urine collections were completed every 4 wk to determine study compliance via para-aminobenzoic acid excretion. Results Of the participants enrolled in the trial, 123 completed the 12-wk intervention. Sucrose and saccharin consumption led to increased body weight across the 12-wk intervention (Δweight = +1.85 ± 0.36 kg and +1.18 ± 0.36 kg, respectively; P ≤ 0.02) and did not differ from each other. There was no significant change in body weight with consumption of the other LCS treatments compared with baseline, but change in body weight for sucralose was negative and significantly lower compared with all other LCSs at week 12 (weight difference ≥ 1.37 ± 0.52 kg, P ≤ 0.008). Energy intake decreased with sucralose consumption (P = 0.02) and ingestive frequency was lower for sucralose than for saccharin (P = 0.045). Glucose tolerance was not significantly affected by any of the sweetener treatments. Conclusions Sucrose and saccharin consumption significantly increase body weight compared with aspartame, rebA, and sucralose, whereas weight change was directionally negative and lower for sucralose compared with saccharin, aspartame, and rebA consumption. LCSs should be categorized as distinct entities because of their differing effects on body weight. This trial was registered at clinicaltrials.gov as NCT02928653.

Each of the macronutrients, carbohydrate, protein and fat, has a unique set of properties that influence health, but all are a source of energy. The optimal balance of their contribution to the diet has been a long-standing matter of debate. Over the past half century, there has been a progression of thinking regarding the mechanisms by which each may contribute to energy balance. At the beginning of this time period, the emphasis was on metabolic signals that initiated eating events (i.e., determined eating frequency). This was followed by an orientation to gut endocrine signals that purportedly modulate the size of eating events (i.e., determined portion size). Most recently, research attention has been directed to the brain where the reward signals elicited by the macronutrients are viewed as potentially problematic (i.e., contribute to disordered eating). At this point the predictive power of the macronutrients for energy intake remains limited.

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 6 1 years; BMI: 29.7 6 4.6 kg m 22 ) 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 (20.4 6 0.5 kg) vs. CON (11.6 6 0.9 kg; P 5 0.02), whereas NP did not (10.3 6 0.5 kg). HP led to reductions in daily intake (21,724 6 954 kJ) vs. CON (11,556 6 745 kJ; P 5 0.03), whereas NP did not (1494 6 213 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.

Aspartame ingested at 2 doses for 12 wk had no effect on glycemia, appetite, or body weight among healthy, lean adults. These data do not support the view that aspartame is problematic for the management of glycemia, appetite, or body weight. This trial was registered at www.clinicaltrials.gov as NCT02999321.

Snacks, while widely consumed in the United States (U.S.), do not have a standard definition, complicating research to understand associations, if any, with weight status. Therefore, the purpose of this study was to examine the association between snacking frequency and weight status using various snacking definitions that exist in the scientific literature among U.S. adults (NHANES 2013-2016; �20y n = 9,711). Four event-based snacking definitions were operationalized including participant-defined snacks, eating events outside of meals, and operationally defined snacks based on absolute thresholds of energy consumed (>50 kcal). Weight status was examined using body mass index (BMI), waist circumference, and sagittal abdominal diameter risk. Logistic regression models examined snacking frequency and associations with weight status. Outcomes varied by the definition of a snack employed, but the majority of findings were null. Mean energy from snacks was significantly higher among women with obesity compared to women with normal weight when a snack was defined as any event outside of a typical mealtime (i.e. other than breakfast, lunch, dinner, super, brunch), regardless of whether or not it contributed �50 kcal. Further investigation into ingestive behaviors that may influence the relationship between snacking frequency and weight status is needed.