We came across the following video clip on Facebook:
The short clip, taken from a podcast hosted by Steve Bartlett, called “The Diary of a CEO” which has 11.7 million followers on YouTube, contains excerpts from an interview with Dr Sarah Berry, chief scientist at the nutrition company ZOE. In the video, Dr Berry warns that snacking after 9 PM could lead to more belly fat, raised inflammation, and worse cholesterol levels — regardless of whether those snacks are “healthy” or not.
What the expert actually said
Dr. Berry’s warning is rooted in research from the field of chrononutrition — the study of how our internal body clocks affect metabolism. According to her, eating late in the evening can disrupt circadian rhythms, reducing the body’s ability to process glucose and fats efficiently.
She points to tightly controlled clinical trials in which late-night snacks were associated with increased belly fat, higher levels of inflammation markers, and worsened blood lipid profiles (such as cholesterol). Notably, these effects were observed even when the snacks were relatively healthy.
Examining the claim
When we looked into the claim, we found that there is evidence that eating late in the evening can promote fat gain, especially in the abdominal area. A 2022 study by Harvard Medical School investigators at Brigham and Women’s Hospital found that eating four hours later in the day reduced energy expenditure, increased hunger, and shifted fat metabolism toward storage, raising the risk of an increase in accumulation of body fat.
Similarly, a 2017 observational study from the American Journal of Clinical Nutrition (AJCN) reported that the timing of food intake relative to melatonin onset, a marker of a person’s biological night, is associated with higher percent body fat and BMI, and not associated with the time of day, amount or composition of food intake, indicating that the timing of when you consume calories, relative to your own biological timing may be more important for health than the actual time of day. These findings suggest that, regardless of food quality, consistently delaying meals can disrupt circadian metabolism in ways that favour fat accumulation.
Late-night eating has also been linked to increased inflammation and cholesterol levels. A study conducted by the National Yang-Ming University in Taiwan from 2019 found that LDL cholesterol levels can be lowered by eating less at night and shifting late-evening fat intake to earlier in the day. LDL cholesterol, often called “bad” cholesterol, is a type of cholesterol that can build up in your arteries, leading to plaque formation and potentially increasing the risk of heart disease and stroke.
Based on our findings, there is scientific backing for the idea that meal timing matters. Studies have shown that our metabolism is generally more efficient earlier in the day, and that eating close to bedtime can impair blood sugar control and fat metabolism.
However, the blanket statement that this happens “even with healthy snacks” is misleading. While the timing of eating does affect metabolism, protein-dense snacks appear to mitigate much of the negative impact. In some sports nutrition studies, pre-sleep protein supplementation was found to be linked to increases in muscle protein synthesis, muscle mass, and strength, in both sedentary adults, and athletes.
In short: eating after 9 pm can increase the risk of belly fat, inflammation, and higher cholesterol, but the effect is strongest when the late meal is calorie-dense, processed, or high in fat and sugar. With carefully chosen, protein-dense healthy foods and overall good dietary habits, the harm is far less clear-cut. Thus, the claim in the video is misleading and likely false — accurate in principle, but overstated when it comes to all “healthy snacks.”
