The video promotes a “15-minute rule” after eating and discusses metabolism, glucose and brown fat, including a claim about reducing belly fat. The research cited below addresses narrower questions about post-meal glucose and brown adipose tissue; it does not establish a 15-minute rule for reducing abdominal fat.
Evidence on post-meal walking and glucose does not prove belly-fat loss
A randomized crossover trial in 41 adults with type 2 diabetes found that walking for 10 minutes after each main meal was associated with lower post-meal glucose than a single 30-minute daily walk during the two-week study period. This was a group-level result for a specific glucose outcome. It did not prove that walking must begin within 15 minutes or that it reduces abdominal fat.
Brown fat is not a basis for a guarantee
A small study of 11 healthy men measured brown adipose tissue activity after a meal and did not find a direct relationship between that activity and diet-induced thermogenesis. The researchers said the quantitative role of brown fat required further study. This evidence does not support the claim that the body follows a 15-minute cutoff to decide whether food is stored as belly fat.
Use the research within its limits
Walking after a meal may be one form of physical activity for some people, but the cited trial did not test long-term changes in body shape and did not test walking as a replacement for diabetes treatment. People with diabetes, those who use insulin, those at risk of low blood glucose, or anyone with mobility limits should consult their care team before changing their activity.