Is It Safe To Drink A Protein Shake On An Empty Stomach? What To Consider

Protein can be an important macronutrient in your diet to help build muscle, assist weight loss, and control your blood sugar. Although inactive adults should get 0.8 grams of protein per kilogram of body weight per day, you'll need about 1 to 1.5 grams of protein per kilogram if you're active, over 40, or both (via Mayo Clinic). People looking to pack on muscle or compete in endurance races will need even more, somewhere in the 1.2 to 1.7 range.

Even though you see many high-protein cereals, bars, and snacks on the market, most people — especially men – get enough protein through their diet. If you do the math, an active person weighing 150 pounds needs between 68 and 102 grams of protein throughout the day. Yet protein works best to build muscle and repair tissues when your body is in an anabolic state just after your workout. That's why protein shakes are a fast and easy way to kickstart your recovery process. If you're a morning exerciser or you haven't eaten for several hours, you could find yourself drinking a protein shake on an empty stomach. Rest assured, it's completely safe to take a protein shake when your stomach is empty, according to the Cleveland Clinic. In some cases, it might even be a good idea.

Drinking protein shakes throughout the day

Although your body uses protein more efficiently after your workout, that doesn't mean you can't drink protein shakes at other times of the day to help build muscle. A 2022 study in Nutrients found that men on a new strength training program gained more muscle if they had 25 grams of protein either just before bed or just after waking up compared to a control group.

Even adding carbs to your protein shake can help you gain muscle strength, according to a 2015 article in the Journal of Nutrition. Compared to a control group, men who drank a protein shake with 27.5 grams of protein and 15 grams of carbs before sleep had significant gains in muscle size and strength after a 12-week resistance training program.

Drinking a protein shake on an empty stomach might be safe, but it might not be wise to do so while you're exercising. During exercise, your body is busy breaking down muscle rather than trying to digest food. Therefore, drinking a protein shake during your workout won't help your performance (via the Cleveland Clinic). A protein shake before your workout might also feel like a rock in your stomach during your workout (via Prevention).

Protein isn't just for weightlifting

Even if you're not a hardcore weightlifter, protein shakes can help you manage your weight, according to a 2019 study in Nutrition. Starting your day with a protein shake can help you eat less at lunch compared to a high-carb breakfast shake. The study found that soy protein and whey protein breakfast shakes both did well in curbing the appetite. A 2020 article in the Journal of Obesity and Metabolic Syndrome said that protein releases hormones that help you feel full while limiting the release of hormones that make you feel hungry.

If you're hungry just before dinner, a protein shake can help reduce your peak blood sugar. A 2023 article in the American Journal of Clinical Nutrition found that protein shakes help slow the gastric emptying of food in people with type 2 diabetes.

Although it's safe to drink a protein shake on an empty stomach, remember that some weight-loss protein shakes have sugar alcohols that could cause gas or bloating. Because whey protein has lactose, people who are lactose intolerant should look for whey protein isolate, which is free of lactose. It's also a good idea to choose a protein shake that's been tested for impurities by a third party, such as the NSF or Informed Choice (via the Cleveland Clinic).