In this article
Editorial update: September 29, 2026. Text prepared with AI support from the indicated sources. No independent clinical review. General information, not an individual meal plan.
Short answer
It helps some people lose weight, mainly in the short term. But compared to other weight-loss diets, the advantage is small: after one year, results are not significantly different.
What the studies show
Research on keto for weight loss is still limited: most studies had few participants, lasted 12 weeks or less, and had no control group. In these studies, keto showed short-term benefits for some people, such as weight loss and improvements in total cholesterol, blood sugar, and blood pressure.
Longer studies tell the rest of the story. In a meta-analysis of 13 trials lasting 1 to 2 years, keto reduced weight slightly more than a low-fat diet after one year: about 0.9 kg difference. And the Cochrane review, with 61 trials in adults with overweight or obesity, concluded that low-carb diets likely result in little or no difference in weight loss compared to balanced-carbohydrate diets, both between 3 and 8.5 months and between 1 and 2 years.
Why some people lose weight on keto
A clue comes from hunger. In a review of 26 short studies, lasting 4 to 12 weeks, people on a ketogenic diet or a very low-calorie diet reported less hunger than at the start. However, the studies did not compare the two diets to each other, so they do not show that keto is more satiating than another way of eating less.
Why the advantage diminishes over time
In the same meta-analysis of 13 trials, adherence to keto declined over time, which may help explain why the difference appeared at one year but not at two.
Therefore, the useful question is not just “which menu causes weight loss,” but “which menu can I stick to.” If you decide to try it, the step-by-step guide to getting started helps plan your routine from day one.
Does keto lead to more weight loss than other diets?
Based on the studies cited here, not consistently. The Cochrane review addresses low-carb diets in general, not just ketogenic (see the difference between keto and low carb), and found an average difference of about 1 kg in the short term and less than 1 kg in the long term. If your question is what happens in the first month, the article on 30-day results summarizes what is known.
Risks to consider before choosing
For long-term use, suggested negative effects include higher risk of kidney stones and osteoporosis and increased uric acid, and there are still doubts about keto safety in kidney and liver disease, pregnancy, breastfeeding, childhood, and adolescence. Therefore, the recommendation is to talk to a doctor and dietitian before starting, especially if you have any condition, take medication, are pregnant, or breastfeeding.
If you decide to follow it, Walter Willett, professor at Harvard, notes that there are no long-term studies of people on keto and suggests prioritizing unsaturated fats (nuts, seeds, avocado, vegetable oils, and fatty fish). More details in risks and precautions before starting.
Sources
- Harvard T.H. Chan School of Public Health, The Nutrition Source: Diet Review: Ketogenic Diet for Weight Loss
- Cochrane: low-carbohydrate diets or balanced-carbohydrate diets for weight loss and cardiovascular risk
- Harvard T.H. Chan School of Public Health, The Nutrition Source: Emphasizing unsaturated fats on a ketogenic diet
Mariana is passionate about a healthy lifestyle.
