Protein shakes vary widely when it comes to ingredients. Some are high in sugar and low in other vital nutrients, such as vitamins, minerals, healthy fats and dietary fiber. In order to survive, you need enough of these nutrients — in addition to protein and carbohydrates — to stay healthy, have energy and avoid nutrient deficiencies. You can survive on protein shakes if you wish, as long as they provide balanced nutrition and enough calories to meet your needs.
It's possible to survive on protein shakes if they provide all the essential nutrients your body needs for proper functioning. Consult with your doctor first before switching to an all-protein shake diet.
Living Off Protein Powder
Protein is a macronutrient that is vital to your health. It helps build and maintain your body's tissues, including muscle, and it supports healthy immune system function. While getting enough protein is important, it is not the only essential macronutrient. You also need adequate amounts of carbohydrates and fats. Protein powders that are used to make shakes often provide a good amount of carbohydrates, but may be lacking in essential fatty acids. Protein powders are also often deficient in dietary fiber, which improves digestion and lowers the risk of heart disease.
Protein powders as your sole source of nutrition may have other risks. Commercial protein powders can be high in added sugars, with more than 20 grams per serving, according to Harvard Health. If you have protein shakes for breakfast, lunch and dinner, you could be consuming upward of 60 grams of sugar per day. Sugar provides no nutritional value, and it contributes to weight gain, obesity and type 2 diabetes, and it affects heart health. The American Heart Association recommends an added sugar intake below 25 grams a day for women and below 36 grams per day for men.
Another danger of protein powders is that, as dietary supplements, they are unregulated by the FDA. This means, you can never be sure what you're getting in your chosen protein powder. You could be getting more unhealthy ingredients and fewer nutrients than you think. Protein powders may also be high in toxins, such as heavy metals, bisphenol-A and pesticides.
Meal Replacement Shakes
Protein and meal-replacement shakes may claim to provide the same nutritional value as a whole meal, or 100 percent of the nutrition you need daily. However, these drinks are often fortified with synthetic forms of vitamins and minerals that may not be as effective or bioavailable as nutrients from whole foods. Consuming only these shakes would be similar to eating fortified cereal flakes for breakfast, lunch and dinner. It might cover your bases for a little while, but long term you could be at risk of deficiencies.
Individual calorie and nutrient needs vary widely and depend on body weight, gender and activity level, and health and fitness goals. Premade shakes or suggested serving sizes for powders may contain too many or two few calories and other nutrients.
It's difficult to judge whether the shake is meeting your needs without some very careful calculations. If you add other ingredients to a shake with protein powder, this makes it even more complicated.
Homemade Meal-Replacement Diet
Making your own shakes at home with nutritious ingredients is often a far better option than many commercial options. You can choose your own ingredients and know exactly what you're getting, making it easier to ensure your nutrient needs are being met. Including fresh fruits and vegetables; protein from soy, dairy or another source; as well as nuts, seeds and other healthy ingredients, you could potentially cover all your nutritional needs with a few shakes a day.
Take the time to do some calculations to make sure you're getting enough of what you need to not only survive, but thrive.
- Genetics Home Reference: What are proteins and what do they do?
- USDA: Basic Report: 14067, Beverages, Protein powder soy based
- Harvard T.H. Chan: Fiber
- Harvard Health Publishing: The hidden dangers of protein powders
- American Heart Association: Added Sugars
- Dr. Ben Kim: Synthetic vs. Natural Vitamins