A randomized controlled trial published in JAMA found that the ketogenic diet improved liver health markers in people who lost 10% of their body weight, but the Mediterranean and very low-fat plant-based diets also showed significant liver benefits. According to Gram Research analysis, all three diets improved liver function when combined with weight loss, though through different metabolic mechanisms, meaning the best choice depends on which diet you can actually stick to long-term.
A new study published in JAMA compared three different diets to see which one was best for liver health and weight loss. Researchers looked at how a ketogenic diet (very low carbs), a Mediterranean diet (lots of plants and healthy fats), and a very low-fat diet affected people’s bodies when they lost 10% of their body weight. According to Gram Research analysis, the findings show how different eating patterns impact your liver differently, which matters because liver health is connected to overall wellness. The study helps explain what actually happens in real life when people try these popular diets.
Key Statistics
A 2026 randomized controlled trial published in JAMA compared ketogenic, Mediterranean, and very low-fat plant-based diets and found that the ketogenic diet showed measurable improvements in liver health markers when participants achieved 10% weight loss.
Research reviewed by Gram found that the Mediterranean diet produced meaningful liver health benefits alongside the ketogenic diet in the same 2026 JAMA trial, suggesting multiple dietary approaches can support liver function during weight loss.
The 2026 JAMA study demonstrated that the very low-fat plant-based diet showed advantages for inflammation markers while supporting liver health, indicating that restrictive low-fat approaches offer distinct metabolic benefits compared to ketogenic diets.
The Quick Take
- What they studied: How three different diets affect liver health and metabolism when people lose 10% of their body weight
- Who participated: Adults participating in a randomized controlled trial comparing ketogenic, Mediterranean, and very low-fat plant-based diets (specific sample size not disclosed in abstract)
- Key finding: The ketogenic diet showed improvements in liver health markers, but the real-world benefits depend on how well people can stick to the diet and their individual health situations
- What it means for you: If you’re considering a ketogenic diet for weight loss, it may help your liver, but you should talk to your doctor first. The Mediterranean diet also showed benefits and may be easier to follow long-term for many people
The Research Details
Researchers conducted a randomized controlled trial, which is one of the strongest types of studies. They divided participants into three groups, each following a different diet while losing 10% of their body weight. One group ate a ketogenic diet (very few carbohydrates, mostly fats and proteins). Another group followed a Mediterranean diet (lots of vegetables, whole grains, fish, and olive oil). The third group ate a very low-fat, plant-forward diet (mostly vegetables, grains, and legumes with minimal fat). The researchers then measured how each diet affected liver health and other metabolic markers. This approach allows scientists to directly compare the effects of different eating patterns under controlled conditions.
The liver is your body’s main cleaning organ, filtering out toxins and helping with digestion. When people lose weight, their liver changes significantly. By comparing three popular diets in a controlled study, researchers can see which approach is actually best for liver health, not just for losing pounds. This matters because some diets might help you lose weight but harm your liver, while others might protect liver health while you slim down. Understanding these differences helps people make smarter choices about which diet fits their health goals.
This study was published in JAMA, one of the most respected medical journals in the world. The randomized controlled trial design is considered the gold standard for nutrition research because it reduces bias and allows for direct comparison between groups. However, readers should note that the abstract provided does not include the full sample size, which is important context for understanding how broadly these findings apply. The real-world applicability depends on how similar study participants were to the general population.
What the Results Show
The ketogenic diet showed measurable improvements in liver health markers when participants achieved 10% weight loss. This is significant because the liver often accumulates fat during weight gain, and the ketogenic diet appeared to help reverse this process more effectively than the other diets tested. The improvements suggest that the specific way your body burns fuel (using fat instead of carbohydrates) may have protective effects on liver function. However, the study also found that the Mediterranean diet produced meaningful benefits for liver health, though through different metabolic pathways. The very low-fat plant-based diet also showed positive effects, indicating that multiple dietary approaches can support liver health during weight loss.
Beyond liver health, the study measured other metabolic markers that affect overall wellness. The ketogenic diet showed the most dramatic changes in how the body processes fat and uses energy. The Mediterranean diet demonstrated benefits for heart health markers alongside liver improvements. The very low-fat plant-based diet showed advantages for certain inflammation markers. These secondary findings suggest that each diet has different strengths: the ketogenic diet for rapid metabolic changes, the Mediterranean diet for balanced health benefits, and the plant-based diet for reducing inflammation.
Previous research has shown that weight loss itself improves liver health, but this study adds important detail about which diets might work best. Earlier studies suggested that ketogenic diets could help with fatty liver disease, and this research confirms that finding in a head-to-head comparison. The Mediterranean diet’s benefits align with decades of research showing it supports heart and liver health. This study is valuable because it directly compares these approaches rather than studying them separately, giving people clearer guidance about which diet might suit their needs.
The abstract does not provide the complete sample size, which limits our ability to assess how confident we should be in the results. The study measured liver health at a specific point (after 10% weight loss), so we don’t know if benefits persist long-term or what happens if people regain weight. The study doesn’t tell us how well people actually stuck to each diet in real life, which matters because the best diet is the one you can actually follow. Individual results may vary significantly based on genetics, starting health status, and other lifestyle factors not measured in this trial.
The Bottom Line
If you’re interested in improving liver health through diet, the ketogenic diet shows promise based on this research, but it’s not the only option. The Mediterranean diet offers similar liver benefits with potentially better long-term adherence for many people. Before starting any restrictive diet, consult your doctor, especially if you have existing liver disease or take medications. Start with modest dietary changes rather than dramatic shifts, and focus on sustainable habits you can maintain for years, not just weeks. The confidence level for these recommendations is moderate to high for weight loss benefits, but individual liver health outcomes may vary.
This research is most relevant for people interested in improving liver health through diet, those with fatty liver disease, and anyone considering a ketogenic diet for weight loss. People with diabetes, heart disease, or kidney problems should discuss any major diet change with their healthcare provider before starting. Athletes and very active people should be cautious with ketogenic diets, as they may affect performance. Pregnant women and children should not attempt restrictive diets without medical supervision. People who struggle with food restrictions or have a history of disordered eating should consider the Mediterranean or plant-based approaches, which are less restrictive.
Weight loss typically begins within 2 to 4 weeks on any of these diets, but liver health improvements take longer. Most studies show measurable changes in liver function markers after 8 to 12 weeks of consistent dieting combined with weight loss. Significant improvements in fatty liver disease may take 3 to 6 months. However, these timelines vary based on starting health status, how much weight you lose, and how strictly you follow the diet. Expect gradual progress rather than dramatic overnight changes, and remember that maintaining the diet long-term matters more than short-term results.
Frequently Asked Questions
Does the ketogenic diet actually help your liver?
Research shows the ketogenic diet improved liver health markers in people who lost 10% of body weight, but the Mediterranean and plant-based diets also helped. The best diet for your liver is one you can follow consistently, so discuss options with your doctor.
Is keto better than the Mediterranean diet for weight loss and liver health?
A 2026 JAMA trial found both diets improved liver health, but through different pathways. The Mediterranean diet may be easier to maintain long-term for many people, while keto produces faster initial changes. Individual results vary based on genetics and lifestyle.
How long does it take to see liver health improvements from diet changes?
Measurable liver function improvements typically appear after 8 to 12 weeks of consistent dieting combined with weight loss. Significant improvements in fatty liver disease may take 3 to 6 months. Results depend on starting health status and diet adherence.
Can I reverse fatty liver disease with the ketogenic diet?
The ketogenic diet showed promise for improving liver health markers in this trial, but it’s not a guaranteed cure. Fatty liver disease reversal requires sustained weight loss, consistent diet adherence, and medical monitoring. Talk to your doctor about your specific situation.
Which diet is safest for liver health: keto, Mediterranean, or plant-based?
All three diets showed liver benefits in the 2026 JAMA study when combined with weight loss. The safest choice depends on your individual health conditions, medications, and ability to stick with the diet. Mediterranean and plant-based diets are generally easier to maintain long-term.
Want to Apply This Research?
- Track your daily macronutrient intake (carbohydrates, fats, and proteins) and weight weekly. For ketogenic diet followers, monitor carbohydrate grams to stay under your target (typically 20 to 50 grams daily). For Mediterranean diet followers, track servings of vegetables, whole grains, and fish. Record how you feel, energy levels, and any digestive changes alongside these metrics to identify which diet approach suits your body best.
- Start by choosing one meal per day to align with your selected diet approach rather than overhauling everything at once. If trying keto, replace one carb-heavy meal with a fat and protein-focused meal. If trying Mediterranean, add one extra vegetable serving and swap one cooking oil to olive oil. If trying plant-based, add one legume-based meal per week. Use the app to plan these specific meals in advance and set reminders to prepare them.
- Establish a baseline by taking photos and measurements before starting, then reassess every 4 weeks. Use the app to log weight trends, energy levels, and how your clothes fit rather than obsessing over daily fluctuations. After 8 to 12 weeks, evaluate whether you’re seeing the results you want and whether the diet feels sustainable. If you’re not seeing progress or the diet feels too restrictive, consider switching to one of the other approaches tested in this study. Schedule check-ins with your doctor every 3 months if you have liver concerns.
This article summarizes research findings and is not medical advice. The ketogenic diet and other restrictive diets may not be appropriate for everyone, especially people with liver disease, diabetes, kidney problems, or those taking certain medications. Before starting any new diet, particularly if you have existing health conditions or take medications, consult with your doctor or registered dietitian. This study measured liver health at a specific point in time and does not guarantee long-term results or individual outcomes. Results vary based on genetics, starting health status, and diet adherence. If you experience unusual symptoms, fatigue, or digestive problems while dieting, stop and seek medical attention immediately.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.