Protein is an essential macronutrient that plays a vital role in numerous bodily functions, including muscle building, tissue repair, and enzyme and hormone production. While adequate protein intake is crucial for overall health, consuming excessive amounts, such as following a 150-gram protein diet, may have both benefits and risks. This article explores the potential advantages and disadvantages of a high-protein diet, providing insights into how to balance protein intake for optimal health.
How Much Protein Do You Need?
Determining the appropriate amount of protein intake can be tricky. The Academy of Nutrition and Dietetics recommends that the average person eat about 0.8 grams of protein per kilogram of body weight each day, or 0.35 grams per pound. For instance, a 165-pound person would need at least 60 grams of protein in a day. The Dietary Guidelines for Americans 2020-2050 recommends adults get between 10% and 35% of their daily energy intake from protein. The Institute of Medicine recommends 0.8 grams of protein per kilogram of body weight. For someone who weighs 150 pounds, that means 54 grams of protein per day.
However, protein requirements can vary depending on several factors, including:
Activity Level: Physically active individuals, especially those involved in strength training or endurance sports, generally require more protein to support muscle repair and growth. For people who exercise regularly, about 1.1-1.5 grams per kilogram are needed. People who regularly lift weights or are training for a running or cycling event need 1.2-1.7 grams per kilogram.
Age: Protein needs increase around age 50 to maintain muscle mass. The American College of Sports Medicine (ACSM) recommends aiming for closer to 1 gram per kilogram of body weight (that’s about 0.45 grams per pound) to maintain muscle mass.
Read also: Muscle-Building Diet
Overall Health: Certain medical conditions, such as kidney disease, may necessitate adjustments in protein intake.
Pregnancy and Breastfeeding: Pregnant and breastfeeding women require more protein to support fetal development and milk production. Pregnant or nursing women of all ages require 71 g of protein per day.
It's best to talk to your healthcare provider before making any diet changes.
Benefits of a High-Protein Diet
A high-protein diet, typically defined as exceeding the recommended dietary allowance (RDA) of 0.8 grams of protein per kilogram of body weight per day, may offer several potential benefits:
Weight Management
Protein can promote weight loss and weight management. High-protein foods tend to promote a feeling of fullness, helping reduce hunger cravings and overeating. Consuming more protein than the body needs can cause side effects and increase the risk of certain conditions.
Read also: Risks of a 100-Gram Protein Diet
Increased Satiety: Protein increases the production of hormones like PYY and GLP-1, both of which help you feel full and satisfied. A 2020 review also found that protein reduces levels of ghrelin, known as the “hunger hormone.”
Boosted Metabolism: Higher protein intake may boost your basal (BMR) and resting (RMM) metabolic rates, helping you burn more calories. Protein may also increase how much energy your body uses to absorb, metabolize, and store food, known as the thermic effect of food (TEF).
Muscle Mass Preservation: During weight loss, a higher protein intake can help protect against muscle loss and keep your metabolic rate up. A 2020 review found that increasing protein intake promotes weight and fat loss while retaining muscle mass. The authors also note that high protein intake has long-term weight loss benefits and could help prevent weight regain.
Muscle Growth and Repair
Protein is essential for building and repairing tissues, making it crucial for muscle growth and recovery after exercise. The International Society of Sports Nutrition's® position stand on protein states that “protein intakes of 1.4-2.0 g/kg/day for physically active individuals is not only safe but may improve the training adaptations to exercise training”.
Other Potential Benefits
In addition to weight management and muscle growth, protein may also help:
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- Reduce muscle loss during aging
- Reduce bone loss
- Improve wound healing
- Increase cardiovascular health
- Increase energy
- Improve gut health and digestion
Risks of a High-Protein Diet
While a high-protein diet can offer several advantages, it's essential to be aware of the potential risks associated with excessive protein intake:
Kidney Issues
High amounts of protein make your kidneys work harder, which can cause kidney damage or make existing kidney problems worse. High-protein diets aren’t recommended for people who have kidney troubles. Low fluid intake and excessive intake of protein are important risk factors for kidney stones. In a prospective cohort study, high total protein intake, particularly high intake of nondairy animal protein, may accelerate renal function decline in women with mild renal insufficiency.
Increased Kidney Stress: High amounts of protein make your kidneys work harder, which can cause kidney damage or make existing kidney problems worse. High-protein diets aren’t recommended for people who have kidney troubles.
Kidney Stones: Protein ingestion increases renal acid excretion, and acid loads, in turn, may be buffered in part by bone, which releases calcium to be excreted by the kidney. This protein-induced hypercalciuria could lead to the formation of calcium kidney stones.
Bone Health Concerns
Some studies suggest that high protein intake, particularly from animal sources, may lead to increased calcium excretion and potentially affect bone health.
Calcium Loss: A diet which is high in protein generates a large amount of acid in body fluids. The kidneys respond to this dietary acid challenge with net acid excretion, and, concurrently, the skeleton supplies buffer by active resorption of bone resulting in excessive calcium loss.
Increased Fracture Risk: In a prospective study, protein was associated with an increased risk of forearm fracture for women who consumed more than 95 g per day compared with those who consumed less than 68 g per day.
Increased Cancer Risk
Some research suggests a possible link between high red meat consumption and an increased risk of certain cancers, such as colorectal cancer.
Formation of Harmful Compounds: Possible mechanisms include the formation of heterocyclic amines in meat when it is cooked. NH3 and N-nitroso compounds (NOC) formed from residues by bacteria in the large bowel are probably also important.
Elevated Cancer Risk: In a cohort study, an elevated risk of colon cancer was associated with red meat intake. The multivariate odds ratios (ORs) for the highest tertile of red meat intake (≥7 times/week) compared with the lowest (≤3 times/week) were 1.6 for stomach, 1.9 for colon, 1.7 for rectal, 1.6 for pancreatic, 1.6 for bladder, 1.2 for breast, 1.5 for endometrial, and 1.3 for ovarian cancers.
Other Potential Risks
Digestive Issues: Eating too much protein, especially in the form of red meat, can bring on unwelcome tummy troubles like bloating, constipation and diarrhea. Eating large amounts of protein can cause gastrointestinal symptoms.
Bad Breath: Eating too much protein, especially without a balanced amount of carbs, can cause ketosis, a metabolic state that happens when your body starts burning fat for energy. “Keto breath,” as it’s called, is one of the side effects.
Dehydration: Your kidneys are responsible for filtering waste from your blood, including the byproducts of protein. They need water to make the process work smoothly, but when they’re stressed - like when you consume too much protein - you can end up dehydrated.
Extra Calories: High protein intake also means ingesting excess calories. Your body turns excess protein into fat, so it’s important to know how much you need in order to maintain your weight (or to lose weight, if that’s your goal).
Balancing Protein Intake for Optimal Health
To reap the benefits of protein while minimizing potential risks, consider these tips:
Determine Your Individual Needs: The first step in getting enough (but not way too much) protein is determining what your personal recommended daily intake, or RDI, is. Again, the USDA’s DRI calculator is a good starting point, but your doctor or a registered dietitian can provide personalized advice on the ideal amount given your activity levels.
Choose High-Quality Protein Sources: The healthiest diet is a balanced, well-rounded diet - one that includes protein, yes, but also complex carbohydrates, healthy fats, and a variety of vitamins and minerals. Skip the processed meats and limit red meat to one to two servings per week, or less than 3 to 6 ounces per week if you have heart disease or high cholesterol. When it comes to animal protein, look for lean, grass-fed meats or wild-caught fish, and whenever possible, organic is best.
Include Plant-Based Protein Sources: Meat isn’t the only way to get your fill of protein. Lentils, beans and nut butters are easy and nutritious sources, too. A variety of animal and plant protein sources is best for your overall health and for reducing your risk of chronic diseases.
Space Out Protein Intake: Your body can only process about 20 to 40 grams of protein at a time, so don’t go too overboard in any one meal. Make sure you’re distributing your intake evenly throughout the day. General recommendations are to consume 15-30 grams of protein at each meal. Studies show that higher intakes in one sitting - more than 40 grams - are no more beneficial than consuming the recommended 15-30 grams at one time. Spread it out. If you’re extremely active and working on building muscle, when you have protein may help you meet your goals.
Stay Hydrated: Drink plenty of water to help your kidneys function properly and prevent dehydration.
Monitor Your Health: Pay attention to any signs or symptoms that may indicate excessive protein intake, such as digestive issues, bad breath, or foamy urine.
A dietitian can advise on how much protein a person should aim for based on their circumstances.
Sample High Protein Meal Plan
Here’s a sample menu that provides about 100 g of protein per day. You can adjust the portions to meet your needs.
- Monday
- Breakfast: 3 eggs, 1 slice whole grain toast with 1 tablespoon almond butter, and 1 pear.
- Lunch: Fresh avocado and cottage cheese salad and an orange.
- Dinner: 6 ounces (oz) (170 g) steak, sweet potato and grilled zucchini.
- Tuesday
- Breakfast: Smoothie made with 1 scoop protein powder, 1 cup coconut milk, and strawberries.
- Lunch: 4 oz (114 g) canned salmon, mixed greens, olive oil and vinegar, and an apple.
- Dinner: 4 oz (114 g) grilled chicken with quinoa and Brussels sprouts.
- Wednesday
- Breakfast: Oatmeal and 1 cup plain Greek yogurt with 1/4 cup chopped pecans.
- Lunch: 4 oz (114 g) chicken mixed with 1 avocado, red bell pepper, and peach.
- Dinner: Turkey pumpkin chili and brown rice.
- Thursday
- Breakfast: Omelet made with 3 eggs, 1 oz cheese, chili peppers, black olives and salsa, and an orange.
- Lunch: Leftover turkey pumpkin chili and brown rice.
- Dinner: 4 oz (114 g) halibut, lentils, and broccoli.
- Friday
- Breakfast: 1 cup cottage cheese with 1/4 cup chopped walnuts, diced apples, and cinnamon.
- Lunch: 4 oz (114 g) canned salmon mixed with healthy mayo on sprouted grain bread, and carrot sticks.
- Dinner: Chicken meatballs with marinara sauce, spaghetti squash, and raspberries.
- Saturday
- Breakfast: Frittata made with 3 eggs, 1 oz cheese, and 1/2 cup diced potatoes.
- Lunch: Leftover chicken meatballs with marinara sauce and spaghetti squash with an apple.
- Dinner: Fajitas with 3 oz (85 g) shrimp, grilled onions, bell peppers, guacamole, and 1/2 cup black beans on a corn tortilla.
- Sunday
- Breakfast: Protein pumpkin pancakes topped with 1/4 cup chopped pecans.
- Lunch: 1 cup plain Greek yogurt mixed with 1/4 cup chopped mixed nuts and pineapple.
- Dinner: 6 oz (170 g) grilled salmon, with potatoes and sautéed spinach.