Protein powder can be an excellent addition to your diet for a convenient post-workout supplement or if you just can't get enough whole-foods protein in your day-to-day eating plan. But because a high intake of protein can cause dehydration and optimal hydration is always so important, remaining aware of how much you get of each is crucial. You may need to up your focus on getting more fluids if your use of protein powder is well above the recommended daily intake.
How much water you drink doesn't depend so much on your protein powder intake. Instead, consider your size, activity level, sweat rate and age. The best way to determine the amount of water you should drink daily is by ensuring your urine is always the color of lemonade.
Average Protein Needs
Protein needs in humans vary widely. For the average person, 1.0 to 1.6 grams of protein per kilogram of body weight per day is recommended. This is equal to 0.45 to 0.73 grams per pound. A 2016 analysis in Food and Function states that chronic high-protein intake of 2 grams per kilogram of body weight per day (or 0.9 grams per pound) could be safe for healthy adults and could help with satiety, weight loss and exercise recovery.
The upper limit for human protein consumption is 3.5 grams per kilogram of body weight (or 1.6 grams per pound) per day — and this is for people well-adapted to a high-protein diet. This means a 150-pound person should eat no more than 240 grams of protein per day.
Whole foods are the optimal source of protein because they contain numerous other vitamins, minerals and healthy fats in addition to protein, explains a 2018 paper published in Nutrients. But if you find protein powder super convenient after a workout or when you just can't get to a whole-food source of the macronutrient, it's an OK addition to your diet.
Just keep in mind that, as a processed food that's been stripped of many quality nutrients, protein powder should be only a part of your total daily intake of protein. Protein powders come in many varieties including whey, casein, soy, egg and pea.
While whey protein is often lauded as an exceptional form of protein, other versions can offer many benefits. Casein, for example, may be most valuable when ingested before bed to prevent overnight loss of muscle mass explains a study published in a 2019 issue of Frontiers in Nutrition, while whey protein powder is superior after a hard workout.
High Protein Diets and Dehydration
Negative effects of too much protein in the diet can include digestive upset, irritation, diarrhea, fatigue, headaches and an increased risk of cardiovascular disease, explains the Food and Function analysis. Dehydration is a very possible side effect, too.
When you consume too much protein, you tax your kidneys. Increased protein consumption increases your body's need to get rid of waste such as urea. To keep the kidneys working smoothly, it's important to consume more water to avoid dehydration, explains research published in Advances in Nutrition in 2015.
Read more: How to Use Protein Powder for Weight Loss
Basic Water Needs
No specific number of ounces of water is recommended for every person. Hydration needs vary according to age, activity level, size and climate. The Academy of Nutrition and Dietetics recommends keeping tabs on the color of your urine.
Its color first thing in the morning is a great indicator of hydration status. If you see urine the color of apple juice, you may be dehydrated and probably could benefit from more water throughout the day. Lemonade-colored urine is desirable, indicating adequate hydration.
Protein and Water Intake
If you're taking in a lot of protein — somewhere around the recommended upper limit of 1.6 grams per kilogram of body weight — you'd benefit from additional fluids, whether that protein is coming from whole foods or protein powder.
Monitor the color of your urine, your physical performance and your digestive health to determine exactly how much water you need. Start with eight 8-ounce glasses per day and increase as needed. Remember that other foods, such as watery vegetables and fruits, contribute to your fluid intake.
Rehydration After Sports Activity
Water is usually recommended after athletic activity, especially if you sweat a lot or if you were working out in hot conditions. You do benefit from a post-workout carbohydrate refuel to boost depleted glycogen, or energy, stores in your muscles. Adding protein post-workout is also of benefit to recovery and muscle repair.
Amino Acids published 2014 research suggesting that, when protein is added to a carbohydrate-electrolyte rehydration drink, it could benefit your recovery and results of your workout. In the research, an added 20 grams of whey protein didn't inhibit rehydration needs, so you shouldn't need more than usual even if you add protein powder to your post-workout hydration strategy.
Protein Powder to Water Ratio
Exactly how you mix your protein powder into a drink depends on the brand you use, the serving size and your personal preference. A standard mixture for many protein powders is one scoop per 20 ounces of water. But, you may prefer a thicker or thinner delivery. Experiment with different amounts to find the ratio that's best for you.
If you do go for a thinner protein-to-water ratio approach, you may benefit from an extra glass of water somewhere in your day. But, if you eat plenty of fruits and vegetables, moderate your coffee and tea intake and liberally quench your thirst throughout the day, you're probably well hydrated.
Read more: The Best Protein Powder for Gaining Muscle
Protein Powder Dehydration
It's unlikely that consumption of protein powder along with a balanced diet will lead to dehydration. But, if you're including the supplements as part of a very high-protein diet plan, do pay extra attention to your fluid intake.
Look for signs of dehydration, including dark-colored urine and unexplained fatigue. There's no magic formula to follow regarding how much water you should take to correct dehydration due to protein intake. Just keep adding water to your diet until your urine is a light yellow and you feel energetic again.
- Food and Function: "Dietary Protein Intake and Human Health"
- Nutrients: "Achieving Optimal Post-Exercise Muscle Protein Remodeling in Physically Active Adults Through Whole Food Consumption"
- Advances in Nutrition: "Controversies Surrounding High-Protein Diet Intake: Satiating Effect and Kidney and Bone Health"
- Academy of Nutrition and Dietetics: "Hydrate Right"
- Amino Acids: "Effect of Whey Protein Isolate on Rehydration After Exercise"
- Academy of Nutrition and Dietetics: "Protein and the Athlete — How Much Do You Need?""
- Frontiers in Nutrition: "The Impact of Pre-sleep Protein Ingestion on the Skeletal Muscle Adaptive Response to Exercise in Humans: An Update"