Fact-Checking Mike Mentzer’s Diet Advice

Mike Mentzer’s Diet Philosophy

Mike Mentzer believed one must focus on intense resistance training before considering any diet plan. He argued that even the best diet will not result in muscle growth unless coupled with optimal training.

Mentzer also criticized the irrational overeating often associated with bodybuilding diets and advised a more rational approach based on the actual needs of the body.

“Training beyond need is overtraining; consuming nutrients beyond need is overeating.” -Mike Mentzer.

Mike Mentzer’s diet plan was formulated around gaining 10 pounds of muscle mass in one year without gaining excess fat. The plan focuses on determining the body’s individual energy and nutritional needs.

Determining Calorie Needs

The first step in the Mike Mentzer diet plan is determining your maintenance calories. This means figuring out how much you need to eat to maintain weight. Mentzer recommended keeping a food journal for 3-5 days while tracking your weight.

You have found your maintenance calories if your weight stays the same during those three days. However, if your weight goes up or down, it indicates that you are either over or under your maintenance target. Based on this information, Mentzer used simple logic to determine the calories required for muscle growth or fat loss.

In many of his lectures, Mentzer highlighted that one pound of muscle contains about 600 calories. Therefore, building 10 pounds of muscle in a year requires 6,000 calories or just 16 extra calories per day.

Similarly, Mentzer often cited that one pound of fat contains 3,500 calories. So, if you reduce your daily calorie intake by up to 1,000 calories below your maintenance need, you will create a 7,000-calorie weekly deficit, resulting in a loss of 2 pounds of fat per week.

How Much Protein?

Mike Mentzer frequently pointed out bodybuilder’s obsession with eating more protein. However, his ideology was the opposite and stressed that one does not need to overemphasize protein in one’s diet.

Mentzer’s reasoning behind protein intake goes back to his calculation that you only need 16 extra calories per day. Since muscle tissue is comprised mainly of water and only about 1/4 protein, he suggested that only four extra calories per day should come from protein.

It just so happens that there are four calories per gram of protein. So Mentzer contended that a bodybuilder only requires 1 gram of protein above maintenance to build 10 pounds of muscle per year.

Macronutrient Ratios

Mike Mentzer was a proponent of a high-carb diet and recommended that most of your daily calories come from carbohydrates. He based this on conventional wisdom that weight training burns sugar, and carbohydrates are the most efficient fuel for intense workouts.

Mentzer’s suggested macronutrient ratio for bodybuilding was 60 percent carbohydrates, 25 percent protein, and 15 percent fat. This would generally be considered a relatively high-carb and high-protein diet. At the same time, the dietary fat intake is on the low end of typical recommendations.

Mike Mentzer Macros

• 60% Carbs
• 25% Protein
• 15% Carbs

Mentzer recommended scaling all macronutrients equally when raising or lowering caloric intake for specific bodybuilding goals. In other words, he proposed maintaining the same approximate macronutrient ratio irrespective of your training goal.

Food Choices

Mike Mentzer’s approach was also based on practicality. He expressed that all a person needs to concern themselves with is a well-balanced diet providing all the nutrients their body needs.

​His idea of a well-balanced diet was mainly consuming whole foods like fresh fruit and vegetables, lean meat like chicken breasts, and whole grains like rice and oats, with a limited amount of healthy fats.

However, Mike was also a realist and was perhaps one of the earliest adopters of flexible dieting, where junk food is permitted in moderation. He admits to consuming pancakes and ice cream daily leading up to the 1979 Mr. Olympia contest while consuming 200 grams of carbs per day.

Dietary Supplements

Mike Mentzer was conservative regarding the use of dietary supplements. He saw them as largely unnecessary most of the time and believed commercial interests were the primary driver behind the rise in supplement use.

Mentzer’s approach was guided by the principle that the body absorbs only the required nutrients and nothing beyond that threshold. According to his understanding, excess supplementation offered no additional benefits.

Mentzer’s intake of supplements was strategic and limited only to times when he was concerned with not getting enough micronutrients, such as the calorie-restricted periods leading up to competitions.

Key points of Mentzer’s perspectives on supplements:

• Situational: Only used them sparingly and when in a caloric deficit.
• Essentials: Concentrate on micronutrients during critical times.
• Economical: Don’t waste money on a vast array of supplements.

Mike Mentzer Diet Plan Example

In practice, Mike Mentzer advised his clients to establish their maintenance calories. Then, he would have them add 300-500 calories daily to gain muscle or subtract 300-500 calories daily to lose fat.

For example, if you determine your maintenance needs to be 2,500 calories daily, you might consume 3,000 calories each day to gain muscle. Of those calories, 60% should be from carbs, 25% from protein, and the rest from fats.

That comes out to 1,800 calories from carbs, 750 from protein, and 450 from fat. ​Since carbs and protein have 4 calories per gram and fat has 9 calories per gram, we can determine your macronutrient targets in grams, as shown below.

Mike Mentzer Nutrition Example

• ​Calories – 3,000
• Carbs – 450 grams
• Protein – 188 grams
• Fat – 50 grams

After a week or two, you would assess your weight and strength level, then adjust calories as needed.

Fact-Checking Mentzer’s Diet Advice

Mike Mentzer is often seen as a credible source of information on bodybuilding and nutrition due to his impressive physique and achievements in the field. However, it’s important to note that his views are based on research that is now decades old and may not be relevant today.

Just because Mike Mentzer’s nutrition advice is logical, that doesn’t make it factual.

Therefore, it’s essential to verify Mentzer’s diet assertions with modern-day science and nutritional advancements. When I looked into Mentzer’s claims, I found that much of his advice was either slightly inaccurate or completely incorrect.

The table below shows which of Mentzer’s claims are substantiated by scientific research.