Besides puppies and world peace, almost everything is better in moderation. Although often thought of as a "health food," protein drinks can be high in calories and lacking in other essential nutrients. Fill up on shakes and you may not only gain weight, but also miss out on balanced nutrition.
Too much of any food, no matter how healthy, can lead to weight gain and nutrient imbalances.
What's in a Protein Drink?
There are good protein shakes, bad protein shakes and shakes that fall somewhere in between. Bad news first: Many of the commercial protein drinks on the market and the ones you can buy at smoothie bars aren't good for you. For example, according to USDA data, 12 ounces of one commercial shake has 30 grams of sugar — more than the amount in a can of soda. While the shake offers more nutrition ounce for ounce than soda, that is still more like a dessert than a health-promoting drink.
On the other end of the spectrum are protein shakes made with high-quality protein powders or yogurt and no added sugar. Sweetened with fresh fruit and packed with other nutritious ingredients like leafy greens and seeds, these can boost your nutrition and help you reach your health and fitness goals.
Maintaining Calorie Balance
Still, any shake, no matter how healthy, contains calories. When you consume more calories than you burn in a day, you will gain weight. For example, according to the Department of Health and Human Services, exceeding your calorie needs by 3,500 calories can lead to a pound of weight gain. If you're drinking 500 extra calories from protein shakes each day, you can expect to gain about a pound of weight each week if you're not countering the shakes with increased activity.
Even if you're putting in your time in the gym six days a week and need a lot of extra protein, taking in more calories than you need can lead to fat gain. If you're drinking protein shakes to help with weight loss, you're even more at risk of gaining weight from drinking too many shakes. While protein in any form may aid weight loss due to its effects on appetite and satiety, if caloric intake exceeds expenditure, you will still gain weight.
In addition, protein shakes may not be your best bet for increasing protein intake when trying to lose weight. According to a review published in February 2015 in Trends in Food Science & Technology, liquid calories have less of an effect on satiety than calories from solid foods. For extra protein, you'd be better off eating a chicken breast than drinking a shake.
Potential Protein Problems
Protein powders are sold as dietary supplements, of which the FDA does not evaluate the quality or safety. Therefore, Harvard Medical School warns that there's no way to be sure just what is in your protein powder or if it contains what the manufacturer claims.
Some of the contents could even be toxic. In 2018, the Clean Label Project tested 134 top selling protein powders for industrial and environmental contaminants and found that:
- 70 percent had detectable levels of lead
- 74 percent had detectable levels of cadmium
- 55 percent had detectable levels of bisphenol-A (BPA)
One test sample was shown to have 25 times the allowed regulatory limit of BPA in one serving. If you drank three protein shakes a day made with that protein powder, you would get 75 times the limit. Consuming too much protein powder could increase your risk of toxic doses of these contaminants.
How Much Do You Need?
People often think that when it comes to certain nutrients, more is better. Using supplements to get mega-doses of nutrients hasn't been shown to provide additional benefits; and in most cases, people can get everything they need through whole foods.
But how much protein is that, exactly? It can vary widely. The recommended dietary intake (RDI) set by the Food and Nutrition Board of the National Academies of Medicine is 46 grams for women and 56 grams for men each day. You can get that amount from drinking fewer than three protein shakes a day.
Those recommendations are based off an estimate of .8 grams of protein per kilogram of body weight. Therefore, a 150-pound person needs about 55 grams of protein daily — inline with the RDI. However, if you weigh more than that, say 190 pounds, your protein needs will be higher than the RDI — 69 grams.
But there may be a benefit to getting more if you have specific goals such as building muscle or losing weight. According to the Academy of Nutrition and Dietetics and the International Society of Sports Nutrition (ISSN), recreational athletes need between 1.2 and 2 grams of protein per kilogram of body weight.
For weight loss, the ideal intake will vary depending on your activity level and the calories you are getting from carbs and fats. In a study published in Obesity Facts in June 2017, people who ate a high-protein diet consisting of 1.34 grams of protein per kilogram of bodyweight lost significantly more weight than those who ate a standard-protein diet providing close to the RDI.
Best Protein Choices
There is nascent evidence that even higher protein intakes of above 3 grams per kilogram in resistance-trained athletes may have positive effects on body composition, according to the ISSN, but there is not enough research to recommend such a high intake at this time. There's also a limit to how much protein your body can use at once, depending on your age and exercise intensity. The ISSN recommends getting 20 to 40 grams per meal.
According to the Academy of Nutrition and Dietetics, even athletes can get all the protein they need from whole foods without drinking protein shakes. While protein drinks are convenient, they should not be your main source of the nutrient. Filling up on shakes can cause you to consume too many calories, and it can also keep you from eating other foods that offer essential nutrients like dietary fiber and healthy fats.
If you want to include a protein drink in your daily diet, make sure it fits into your overall calorie intake for the day. Choose a high-quality shake without added sugar, then get the rest of your protein from healthy sources like fish, chicken, nuts and beans.
- USDA: "Full Report (All Nutrients): 45216726, Protein Drink, UPC: 850250005023"
- USDA: "Full Report (All Nutrients): 45239211, Arizona, Soda Shaq, Orange Cream Soda, Orange, Upc: 613008737443"
- Department of Health and Human Services: "Chapter 5. A Calorie Is a Calorie, or Is It?"
- Harvard Health Publishing: "The Hidden Dangers of Protein Powders"
- Clean Label Project: "2018 Protein Powder Study"
- National Academies of Medicine: "Summary Tables, Dietary Reference Intakes"
- Academy of Nutrition and Dietetics: "Protein and the Athlete — How Much Do You Need?"
- Journal of the International Society of Sports Nutrition: "International Society of Sports Nutrition Position Stand: Protein and Exercise"
- Obesity Facts: "Effect of a High-Protein Diet versus Standard-Protein Diet on Weight Loss and Biomarkers of Metabolic Syndrome: A Randomized Clinical Trial"