Six Weeks of Morning Fasting Causes Little Adaptation of Metabolic or Appetite Responses to Feeding in Adults with Obesity

Eating versus skipping breakfast has no discernible effect on obesity-related anthropometric outcomes: a systematic review and meta-analysis

Background: Eating or skipping breakfast for weight interests scientific and lay communities. Our objective was to systematically review and meta-analyze causal effects of eating versus skipping breakfast on obesity-related anthropometric outcomes in humans. Methods: Six databases were searched for obesity- and breakfast-related terms (final search: 02 JAN 2020). Studies needed to isolate eating versus skipping breakfast in randomized controlled trials. Mean differences were synthesized using inverse variance random effects meta-analysis for each outcome. Positive estimates indicate higher outcomes in breakfast conditions (e.g., weight gain). Leave-one-out sensitivity analysis, secondary baseline habit-by-breakfast assignment analysis, and study duration cumulative analysis were performed. Risk of bias was assessed using Cochrane risk of bias tool. Results: Ten articles (12 comparisons; 6d-12wk) were included. Conditions included recommendations to eat versus skip breakfast, or provision of some or all meals. 95% confidence intervals of all main analyses included the null value of no difference for each outcome: body weight (0.17 kg [-0.40,0.73], k=12, n=487, I 2=74.5), BMI (0.07 kg/m 2 [-0.10,0.23, k=8, n=396, I 2=54.1), body fat percentage (-0.27% [-1.01,0.47], k=6, n=179, I 2=52.4), fat mass (0.24 kg [-0.21,0.69], k=6, n=205, I 2=0.0), lean mass (0.18 kg [-0.08,0.44], k=6, n=205, I 2=6.7), waist circumference (0.18 cm [-1.77,2.13], k=4, n=102, I 2=78.7), waist:hip ratio (0.00 [-0.01,0.01], k=4, n=102, I 2=8.0), sagittal abdominal diameter (0.19 cm [-2.35,2.73], k=2, n=56, I 2=0.0), and fat mass index (0.00 kg/m 2 [-0.22,0.23], k=2, n=56, I 2=0.0). Subgroup analysis showed only one statistically significant result. The interaction effect for BMI (–0.36[-0.65,-0.07]) indicates assignment to conditions consistent with baseline habits had lower BMI. Leave-one-out analysis did not indicate substantial influence of any one study. Conclusions: There was no discernible effect of eating or skipping breakfast on obesity-related anthropometric measures when pooling studies with substantial design heterogeneity and sometimes statistical heterogeneity. Registration: PROSPERO CRD42016033290.

Association of breakfast skipping with cardiovascular outcomes and cardiometabolic risk factors: an updated review of clinical evidence

"Eat breakfast like a king, lunch like a prince and dinner like a pauper" (Adelle Davis, 1904-1974) is a concept that appears to align with some contemporary evidence concerning the appropriate proportioning of daily meals. At the same time, with the popular and scientific dissemination of the concepts of intermittent fasting and time-restricted feeding, well-controlled clinical trials have emerged showing the safety or even possible benefits of skipping breakfast. In this comprehensive literature review, we discuss recent evidence regarding breakfast intake, cardiovascular outcomes and cardiovascular risk markers. Overall, breakfast omission appears to be associated with a higher risk for atherosclerotic and adverse cardiovascular outcomes. However, caution should be employed when deciphering these data as many complex, unmeasured confounders may have contributed. Unfortunately, long-term randomized, clinical trials with detailed dietary control that have assessed clinical outcomes are sparse. Notwithstanding the observational findings, current trials conducted so far-albeit apparently smaller number-have shown that breakfast addition in subjects who do not habitually consume this meal may increase body weight, particularly fat mass, through caloric excess, whereas skipping breakfast may be a feasible strategy for some people aiming for calorie restriction. To date, definitive benefits of breakfast omission or consumption are not supported by the best evidence-based research, and the question of whether skipping breakfast per se is causally associated with cardiovascular outcomes remains unresolved.