The Undeniable Metabolic Benefits of High Protein Diets

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Is a high-protein diet the best diet you could follow? If so, what are the health benefits? Are there any risks?

Read on, and you’ll understand why I believe a high-protein diet is the best diet for health, fitness, and even supporting quality-of-life later in life.

What is a High-Protein Diet?

Researchers categorize diets as “high-protein” based on the percentage of calories coming from protein or the measured amount of protein you eat compared with your body weight.

Percentage-Based Calculation: According to The Institute of Medicine, a high-protein diet consists of more than 30-35% of its total calories as protein. If you eat 2000 calories per day and consume more than 600-700 calories from protein, you’d eat a “high-protein diet.”

Weight-Based Calculation: The Institute of Medicine also set the Recommended Daily Intake (RDI) for protein at 0.8 grams per kilogram of bodyweight. That’s 0.36 grams per pound bodyweight. Using this method, if you weigh 200 pounds and eat more than 72 grams of protein per day, according to the IOM, you’d eat a “high-protein diet.”

The weight-based calculation generates a better recommendation. For example, a 200-pound athlete that trains five hours per day requires far more calories than a 200-pound couch potato. Yet, most of the additional calories should come from fat or carbohydrates to fuel exercise.

That said, 0.8 grams per kilogram is the Recommended Daily Intake, which is an “adequate amount for most people to avoid deficiency.” It is not an optimal amount.

In the United States, the average adult male eats 98 grams of protein per day, and the average female eats 68 grams. That’s pretty close to the Recommended Daily Intake.

Yet, the RDI is well-below optimal.

From my experience, experimentation, and based on an increasing amount of evidence, the optimal protein intake is about one gram per pound ideal body weight.

I always include the phrase “ideal body weight,” because if you weigh 250 pounds today, but should be closer to 150 pounds, 150 grams of protein would be optimal. It’s not that 250 grams would be detrimental; it’s unnecessary to eat the extra 100 grams.

The ‘lay’ recommendation to consume 1 g protein/lb of body weight (2.2 g/kg/day) while resistance training has pervaded for years. Nutrition professionals often deem this lay recommendation excessive and not supported by research. However, as this review shows, this ‘lay’ recommendation aligns well with research that assesses applied outcome measures of strength and body composition in studies of duration > 4 weeks.

Bosse JD, Dixon BM, 2012

What are the health benefits of a high-protein diet?

High-protein diets don’t just help you look better. They also impact your overall health. The following are some of the most significant ways high-protein diets enhance your wellbeing.

Supports fat and weight loss

In one type of study, researchers create a specific dietary protocol, where protein makes up 30-35% of calorie intake in one group, and less in another. They equalize total calories between the groups, relative to each individual’s metabolic rate. In such studies, the higher-protein group experiences more of an improvement in body composition.

In another study design, participants follow an ad libitum diet. They must eat a set level of protein, but get no other dietary recommendations. In this type of study, higher-protein intake favors better body composition as well.

When I work with online personal training clients on their nutrition, my first recommendation is to increase protein intake. I don’t care what other carbs and fat they eat, as long as they eat more protein. They almost always eat fewer carbs and less fat without thinking about it, and get leaner without feeling like they’re on “diets.”

High-protein diets:

Increase satiety: Protein stimulates the release of cholecystokinin, PYY, and GLP-1, which reduce feelings of hunger, as well as increase satiety, prolonging the length of time before hunger returns. The hormones alter signals in your brain about food needs.

Fill you up faster during a meal: By eating more protein, you’ll unconsciously eat less fat and carbohydrate. This is even more effective if you eat all of your protein at the beginning of your meal.

Stimulate diet-induced thermogenesis: Though it’s a small metabolic difference, you burn about five times as many calories digesting and assimilating protein as you do fat or carbohydrate.

For every 100 calories of protein you eat, your body burns about 25 calories just to digest and absorb it. In comparison, your body only burns about 8-10% of carbohydrates and 3-5% of fat.

Not only is a high-protein diet more effective for weight loss, it’s also more effective for keeping the weight off once you’ve lost it. Many people rebound after reaching their goal weight, but a high-protein diet can help you maintain a leaner body once you’ve achieved it.

Even after a year, those on a higher protein diet and without specific calorie goals, are more likely to maintain weight loss.

Increases muscle growth or helps maintain muscle mass

Muscle is a quality-of-life savings account. The more you have later in life, the longer you’ll be able to experience your current quality of life and do the things you enjoy doing.

A higher protein diet combined with a well-designed strength training program builds muscle while you’re young enough to build it, and help you maintain it as you reach later adulthood.

Your level of muscle mass can be a better predictor of longevity than your body fat level.

Dietary protein or branched-chain amino acids stimulate protein synthesis and slow protein breakdown.

Research shows a high-protein diet can cause a slight increase in muscle mass if you don’t exercise at all. Of course, the effects will be more significant when combined with weight training.

Enhances bone health

High-protein diets stimulate calcium absorption, bone turnover, and production of insulin-like growth factor 1 (IGF-1).

IGF-1 stimulates osteoblast activity. Osteoblasts secrete the matrix for bone formation.

Integrative health doctors also use IGF-1 as a reference for growth hormone, one of the essential hormones for supporting muscle mass and fat metabolism.

Based on almost 42,000 women, the lower one’s protein intake, the higher the risk of hip fractures.

Protein also has a positive effect on parathyroid hormone, which affects bone health.

While dietary protein increases calcium absorption, it can also increase calcium secretion. Eating some vegetables and taking calcium, magnesium, and vitamins D and K would counteract that loss.

Supports healthy blood sugar levels

Small elevations in blood sugar are normal. Significant short-term increases or even small but chronic increases in blood sugar may lead to insulin resistance and diabetes.

Research shows that a high-protein breakfast lowers blood glucose levels following breakfast, and limits the blood-glucose-raising effects of lunch, as well.

In people with Type 2 Diabetes, a high-protein snack two hours before breakfast, reduced blood glucose increases by 40%.

Elevated blood sugar and triglycerides go hand in hand. So, it’s no surprise that higher-protein weight-loss diets reduce triglycerides more than reduced-calorie, high-carb diets.

Supports a normal stress response

When you’re under stress, your body uses more protein to combat the effects of cortisol and to support your immune system.

Many people who start exercising, or begin a weight loss program, get sick shortly after getting started. It’s often because they add the stress of the diet or exercise without eating sufficient protein to support their immune system and other metabolic needs.

Whenever I can get through to someone who is “always sick,” I encourage them to increase their protein intake. It’s incredible to see how quickly they get over their illness.

Healthy, resistance-trained men followed a diet for two weeks, which was designed to match 60% of their usual calorie intake.

One group ate a high-protein, low-fat diet, and the other ate a moderate-protein, moderate-fat diet. The higher-protein group experienced less fatigue, more satisfaction with the diet, less stress, and less mood disturbance than the moderate-protein group.

Enhances Immune Function

The COVID-19 pandemic cast light on the fragile state of some people’s immune systems. Obesity, diabetes, and other inflammatory conditions significantly increase the risk people will experience severe cases and even death from the virus. Fortunately, people can reverse their obesity, diabetes, and many inflammatory conditions through personal nutrition and lifestyle choices.

In addition, insufficient protein intake makes people more susceptible to infection as well.

In humans, protein malnutrition and increased susceptibility to Zika and influenza viruses is related to cell mediated immunity and decreased bactericidal function of neutrophils, the complement system, and IgA as well as antibody response. Low protein status, characterized by low albumin or pre-albumin levels, but also low iron and vitamin E correlated with lower responses to influenza vaccination in the elderly, thereby highlighting the interrelation between various nutrients and the immune response.

Iddir M, et al.

Frequently Asked Questions

The following are the most common questions clients and members ask, outside of what I’ve already covered. If others come about, I’ll update the list below in the future. If you have a questions that isn’t answered, please post it in the VIGOR Training Facebook group, or leave a comment below.

How much protein do I need to eat to build muscle?

One gram of protein per pound goal body weight should be sufficient. While eating more than one gram per pound would not be detrimental, it makes your diet more expensive and filling.

That said, eating protein alone won’t build muscle. You need to follow a well-designed strength training program consistently and get adequate, deep sleep each night.

Is protein bad for my kidneys?

Because protein metabolism involves the kidneys, some theorize that high protein intake causes kidney damage. It does not.

Research debunked this myth long ago. If someone has pre-existing kidney disease or a history of kidney stones, high protein intake is not appropriate. Protein doesn’t cause this damage, but kidneys that are already compromised may not handle the processing protein’s byproducts.

Researchers showed that diets as high as 1.5 grams of protein per pound bodyweight led to no adverse renal issues.

Do I need to eat a specific amount of protein with each meal?

If possible, I recommend women eat at least 30 grams of protein in a meal, and men at least 40 grams. However, it comes down to the amount you intend to eat each day, divided by the number of meals you eat.

I usually eat two meals per day, so I eat about a pound of meat with each meal. If I ate more meals, I’d eat less with each meal.

Is it true that you can only use 30-40 grams of protein from a meal, and the extra turns into fat?

This myth comes from the fact that protein synthesis gets maximally stimulated by eating 30-40 grams of high-quality protein. If you eat more, you don’t increase protein synthesis to a greater extent.

However, research shows that you do slow protein breakdown more by eating more protein.

On top of that, you use protein for more than building or maintaining muscle. That said, even if you ate more than you needed, it’s almost impossible to convert it to fat. The process of converting the amino acids to glucose, and then converting the glucose to triglycerides and fatty acids requires a substantial amount of energy.

Bottom line: You won’t get fat from overeating protein.

Do older adults need more or less protein?

Older adults need more protein than younger adults to stimulate protein synthesis and decrease protein breakdown at the same level. As you age, you experience “anabolic resistance,” meaning you need to train harder and eat more to generate the same muscle-building impact.

Older adults also lack digestive enzymes and hydrochloride, which are essential for digesting and assimilating protein.

What happens if I overeat protein?

If you eat too much protein, you’ll feel full. That’s pretty much it.

Protein intakes of 2.0 grams per pound bodyweight did not increase body fat levels, and slightly improved muscle mass and cardiovascular health markers when compared to those eating 1 gram per pound body weight.

What are the best high protein foods?

Whey protein is hands down, the best protein source, although other dairy protein sources, and other animal proteins are critical for long-term health and fitness. The following are other protein-rich foods you can use for quick and healthy meals:

• Chicken breast
• Chicken thighs
• Cottage cheese
• Eggs
• Filet Mignon
• Ground beef (lean)
• Ground bison
• Ground turkey
• Ham
• Low-sugar Greek yogurt
• New York strip steak
• Pork loin
• Pork shoulder steak
• Round steak
• Pork loin

Do I need to time my protein with exercise?

Unless you are a high-performing athlete, protein timing isn’t as important as simply “getting enough protein.”

What if I don’t have access to grass-fed, wild-caught, organic protein sources?

Do the best that you can. Don’t let “the best option” keep you from “the good one.” Too many people complain about conventional food options in front of them, and because they can’t eat the perfect protein source, they instead eat a bagel, chips, candy, or other junk. If all you have as an option is something less than the best, it’s better than not eating it at all.

What should I do if I’m vegetarian or vegan?

Find a way to increase your protein intake without using starchy carbohydrate sources.

You’ll probably have to drink at least a couple of plant-based protein powder shakes every day. If you’re vegetarian, and willing to eat dairy, eggs, or even fish, it’ll be a lot easier.

What if I have an allergy or sensitivity?

Find a different protein to eat.

References