Metabolic Types Explained

Generally, metabolic types are divided into three categories: endomorph, mesomorph, and ectomorph. These may also be called somatotypes, phenotypes, or body types.

The main metabolic types correspond to slow, medium, or fast metabolic rates. Your metabolic rate is partially determined by genetics and influences your physical appearance and response to diet.

Endomorph Metabolic Type

Endomorphs tend to have a slower than average metabolism. This makes it easier to gain weight and harder to burn fat. So if you have this metabolic type, you are more likely to be round and soft.

For this reason, endomorphs have to be very diligent in their diets and be careful not to overeat. But this sensitivity to weight gain often leads endomorphs to chronically undereat. Which causes your metabolism to drop even further!

The key to healthy dieting for endomorphs is to find the appropriate calorie deficit that leads to weight loss without damaging your metabolism. Once you dial in your calories, it’s best to eat foods higher in protein and lower in carbs.

Detailed Endomorph Diet

Ectomorph Metabolic Type

Ectomorphs generally have a faster metabolism than average people. This makes it easy to lose weight, but you also have a hard time gaining healthy lean muscle. So you might be unhappy with being skinny but not that muscular.

With a hyperfast metabolic rate, ectomorphs have to be careful not to expend too much energy. Otherwise, you’ll never be able to eat enough to gain weight or build muscle.

The key to healthy eating for ectomorphs is to get enough calories to fuel your metabolic bonfire and your daily activities. Often, you’ll need to increase your carb intake to meet this energy demand. Adequate protein is very important as well.

Detailed Ectomorph Diet

Mesomorph Metabolic Type

Mesomorphs have a metabolic rate somewhere between endomorphs and ectomorphs. For this metabolic type, it’s easy to gain weight but it’s also not as hard to lose it. While this has advantages, you can still be out of shape.

Even with “good genes”, mesomorphs have to pay attention to nutrition in order to reach their fitness goals. The good news is, making small adjustments to your diet and exercise plan can have huge results.

The key to eating for mesomorphs is a goal-specific calorie target, adequate protein intake, and healthy foods that fuel your workouts.

Detailed Mesomorph Diet

Hybrid Metabolic Types

It’s important to realize that there aren’t just 3 neat categories that every person fits into. Instead, metabolic types are a spectrum from fast to slow and everywhere in between.

For this reason, it’s best to include hybrid metabolic types to capture those people who fall somewhere in-between categories. These hybrid types are endomorph-mesomorph and ectomorph-mesomorph.

In reality, hybrid metabolic types are more common than pure types. Based on my body type quiz results from over 100,000 individuals, 2 out of 3 people have a hybrid metabolic type.

Endo-Meso Metabolic Type

Endo-Mesos aren’t as round as pure endomorphs, but they still tend to gain weight easier than most. With this metabolic type, you may gravitate toward a stocky or muscular build with some excess fat.

Therefore, endo-mesos can eat slightly more calories than pure endomorphs. But you’ll benefit from following recommendations similar to that of an endomorph.

Ecto-Meso Metabolic Type

Ecto-Mesos aren’t as skinny as a pure ectomorph, but you will still have a harder time gaining weight than losing it. Your calorie target won’t be as high as an ectomorph, but you should follow some of the same dietary tweaks.

Can You Change Your Metabolic Type?

As I mentioned earlier, your metabolic type is primarily dictated from birth by your genetics. So it’s not likely that your metabolic type will change from one major category to another.

That being said, you can change how your genes are expressed through diet and exercise. And you can significantly alter your metabolism by changing your body composition.

That’s because the amount of lean muscle you have is the biggest contributor to your metabolic rate. So by gaining muscle, you increase your metabolism and make it easier to burn fat.

Also, your metabolic rate decreases with age. But gaining lean muscle counteracts this decrease, thereby lowering your metabolic age.

Figure 8. The direct relationship between lean mass and metabolic rate.