A 60-day ketogenic-diet study found that adults did not all respond the same way. Glucose generally fell, while insulin resistance improved mainly among participants with overweight or obesity. Because everyone followed the diet and there was no comparison group, the changes cannot be credited to ketosis alone.
What changed
Researchers followed adults with normal weight, overweight, or obesity and assessed them before the diet and on days 14, 30, and 60. Blood ketones rose in every group, confirming nutritional ketosis. Body weight, total fat, visceral fat, and subcutaneous fat decreased. Glucose fell after the diet began, but insulin and HOMA-IR—a calculated marker of insulin resistance—improved mainly in the overweight and obesity groups. Lipid, liver-enzyme, appetite, stress, and hormone responses varied by weight category and sex. The peer-reviewed paper was accepted October 22 and published October 28, 2026.
How strong is the evidence?
This was a prospective human intervention with repeated laboratory and body-composition measurements. It was exploratory, had a limited sample, and used a single-arm design rather than randomizing participants to ketogenic and comparison diets.
What remains uncertain
Weight loss and energy-intake changes occurred alongside ketosis, so their effects cannot be separated. The study did not establish long-term safety, fewer cardiovascular events, or superiority to less restrictive diets. Different lipid and liver-enzyme patterns also caution against assuming one response fits everyone.
Why it matters
The useful message is personalization, not that everyone should adopt keto. People using diabetes or blood-pressure medication should discuss major carbohydrate restriction with a clinician because glucose and medication needs can change.
Related: Mediterranean diet, fasting-linked weight loss, and inflammation.
Sources
Original open-access study in Scientific Reports.
Illustrative stock photograph by Brooke Lark on Unsplash; it does not depict study participants, prescribed meals, or results.
