Are Protein Shakes Good for Fatty Liver? Whey and Powders

TL;DR

• Plain whey or other protein powder is generally fine with fatty liver. No liver guideline advises against it, and protein is not something fatty liver diets restrict.
• There is no good evidence that protein shakes treat fatty liver. What counts is total calories and weight loss, so choose low-sugar shakes and count them in your day.
• The real risks are sweetened shakes (up to 25 g of sugar in one bottle) and multi-ingredient “bodybuilding” products, which have been linked to liver injury.

Yes, protein shakes can fit a fatty liver plan, if they are low in sugar and replace other calories instead of adding to them. Plain whey is a sound protein source, and nothing in the major MASLD (metabolic dysfunction-associated steatotic liver disease, formerly NAFLD) guidelines tells you to avoid protein powders.

But a shake will not treat your liver by itself. The two things that matter are the sugar and extras in the product, and whether it helps or hurts your calorie balance.

Is protein bad or good for fatty liver?

Protein is not something fatty liver diets limit. The AASLD (2023) and the 2024 European guideline focus on weight loss, a Mediterranean-style diet with fewer refined carbohydrates, sugary drinks and saturated fat, and exercise. Protein is not on the “avoid” list. The 2025–2030 Dietary Guidelines for Americans set a protein goal of 1.2–1.6 grams per kilogram of body weight a day, adjusted to your calorie needs, and encourage a mix of animal and plant protein foods.

For a 150 lb (68 kg) person, that is about 82 to 109 g a day. Most people can get there from food: eggs, fish, chicken, beans, tofu, Greek yogurt. A shake is a convenience, not a requirement.

One caution: cirrhosis is different. In cirrhosis, protein needs are usually higher and a late-evening snack is often advised. The 2024 European guideline cites 1.2–1.5 g/kg a day for cirrhosis and high-protein diets for sarcopenia. If you have cirrhosis, follow our cirrhosis diet guide and your own care team, not general MASLD advice.

Do protein shakes help fatty liver?

The evidence for whey specifically is limited:

• A 4-week trial in 34 men (published in the Journal of the International Society of Sports Nutrition, 2023) combined daily resistance training and a calorie-controlled diet with either 60 g of whey a day or an isocaloric placebo. Liver fat, measured by FibroScan CAP, fell in both groups, with no significant difference between them by the end. ALT, a liver enzyme, fell only in the whey group, and the authors concluded whey “may not enhance the overall effects of resistance exercise on” liver fat. It was small and short, and the abstract describes the participants as sedentary men, not as people with diagnosed fatty liver.
• Weight loss remains the lever. The guidelines’ targets, about 5% to reduce liver fat and 7–10% or more to improve inflammation and scarring, come from diet and exercise studies, not protein supplements. See how to reverse fatty liver.

So the honest summary is: shakes are neither proven help nor proven harm. They are a tool for hitting a protein target within your calories, and can help keep muscle while you lose weight, which is the reasoning behind many dietitians’ advice. That reasoning is plausible, but I did not find liver-specific trials proving it.

What is in different protein shakes?

Sugar and calories vary widely. Per serving, from USDA FoodData Central:

Product	Serving	Calories	Protein	Sugar	Sodium
Whey protein powder (generic)	1 scoop (32 g)	113	25 g	0 g	50 mg
Milk-based protein powder (“light”)	50 g	198	25 g	2 g	125 mg
Soy protein powder (sweetened)	1 scoop (45 g)	175	25 g	10 g	330 mg
Ready-to-drink milk protein shake	14 fl oz (414 g)	215	24 g	3 g	393 mg
Ensure, ready to drink	8 fl oz (254 g)	267	10 g	25 g	213 mg
Boost Plus, ready to drink	1 bottle (237 g)	327	13 g	20 g	182 mg
Fast-food vanilla milkshake	small, 12 fl oz (298 g)	501	10 g	35 g	298 mg

Source: USDA FoodData Central (SR Legacy). Generic entries; check the label of your product.

Compare those with some whole foods that supply protein:

Food	Serving	Calories	Protein	Sugar
Greek yogurt, plain nonfat	1 container (170 g)	100	17 g	5.5 g (lactose)
Cottage cheese, 2%	1 cup (226 g)	183	24 g	9 g (lactose)
Egg, hard-boiled	1 large	78	6 g	0.6 g
Chicken breast, roasted	3 oz (85 g)	140	26 g	0 g
Tofu, firm	½ cup (126 g)	98	11 g	0.8 g

Source: USDA FoodData Central (SR Legacy).

Takeaways:

• Plain powder is the leanest option: about 25 g of protein for roughly 100–200 calories and little sugar.
• Meal-replacement shakes are sugar-heavy. An 8-ounce Ensure has about 25 g of sugar. The 2025–2030 Dietary Guidelines say one meal should contain no more than 10 g of added sugars. USDA does not separate added sugar from total in these entries, so treat that as an upper bound.
• Milkshakes are not protein shakes. The fast-food shake has 35 g of sugar and 16 g of saturated fat for 10 g of protein.
• Whole foods do the job too, and fill you up more. A Greek yogurt with berries is a protein shake you chew.

What should I look for on the label?

• Added sugar: aim for 5 g or less per serving, and well under 10 g.
• Protein of 20–30 g for the calories. Watch for “protein blends” padded with sugar or maltodextrin.
• A short ingredient list: whey, soy, pea or milk protein, a natural flavor, perhaps a sweetener. Be wary of long lists with herbal extracts, “fat burners”, testosterone boosters or “proprietary blends”.
• Sodium if you watch salt: sweetened soy powder and some ready-to-drink shakes carry 300–400 mg a serving.
• Third-party testing seals from independent labs help confirm the contents match the label, though they do not guarantee safety.

Can protein powders and supplements harm the liver?

Plain protein powder is rarely the problem. The concern is the wider supplement market:

• A review in Hepatology (2017), from an AASLD and NIH symposium, reported that herbal and dietary supplements account for about 20% of drug-induced liver injury cases in the US, based on research data. The main culprits were anabolic steroids, green tea extract and multi-ingredient nutritional supplements, where the toxic component is often unknown.
• A 2019 study from the Drug-Induced Liver Injury Network described 44 young men who developed prolonged cholestatic liver injury, with jaundice in all and itching in 84%, from bodybuilding supplements. Product analysis in some cases found anabolic steroids not listed on the label. None died or needed a transplant, but 71% were hospitalized.

If you already have fatty liver, you have less reason to take risks with your liver. Choose a single-ingredient powder from a reputable brand, avoid products making muscle-building or fat-burning claims, and tell your doctor everything you take. Our article on creatine covers another common gym supplement.

How to use a protein shake in a fatty liver diet

• Replace, don’t add. Swap a shake for a snack or part of a meal, not on top of your usual food.
• Mix with water, unsweetened milk or unsweetened soy milk, not juice or ice cream.
• Add fiber: blend in berries, spinach, oats or chia. Fiber is a target nutrient in fatty liver diets. See are chia seeds good for fatty liver.
• Use it where food is hard: after a workout, on busy mornings, or when appetite is low.
• Keep an eye on the scale and labs. If your weight is not moving, a shake may be adding calories you do not need.

If you log meals in an app like Liverly, you can scan the label and see the sugar and calories next to the rest of your day.

The Bottom Line

Protein shakes are generally fine with fatty liver when they are low in sugar, simple in ingredients and used in place of other calories. Plain whey has no known liver downside for most people, but there is also no strong proof that it helps the liver: weight loss, a Mediterranean-style diet and exercise do that.

Avoid sweetened meal-replacement shakes as a daily habit, steer clear of multi-ingredient “bodybuilding” products, and ask your doctor before supplementing if you have cirrhosis, kidney disease or take medicine.

Sources

• Rinella ME, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology. 2023.
• EASL–EASD–EASO Clinical Practice Guidelines on the management of MASLD. J Hepatol. 2024.
• USDA & HHS: Dietary Guidelines for Americans, 2025–2030.
• Kim CB, et al. Does whey protein supplementation during resistance exercise have additional benefits for decreasing hepatic fat content? J Int Soc Sports Nutr. 2023.
• Navarro VJ, et al. Liver injury from herbal and dietary supplements. Hepatology. 2017.
• Stolz A, et al. Severe and protracted cholestasis in 44 young men taking bodybuilding supplements. Aliment Pharmacol Ther. 2019.

This article is for informational purposes only and is not medical advice. Talk to your doctor or hepatologist about your specific situation.