Understanding bone structure and fat/muscle distribution can help you reach your fitness goals.

Ectomorph: This body type is thin, usually tall, and lanky. Individuals with a sturdy, rounder bone structure have wider hips, stocky limbs and barrel-shaped rib cages.

They struggle to gain weight no matter how many carbs or how much fat they eat.
They usually have a lean build with long limbs and small muscles.
To gain weight naturally, they must load up on carbs and foods full of calories.

Diet:

Most of their calories should come from carbs and at least 25 percent from protein if they want to build muscles.

Workout:

It is also important to indulge in high-intensity interval training and eat something small every two hours. They must be sure to get all necessary nutrients to build strong muscles.

Endomorph: If an individual finds it ridiculously tough to shed fat, then they probably have an endomorphic body type. They tend to gain weight faster. However, they look curvy. Endomorphs usually look broader and have a triangular bone structure, narrower hips, and broader shoulders.

They usually have broad shoulders, narrow hips and shorter limbs. While they have larger muscle mass, they also have a higher fat percentage because they are predisposed to storing fat rather than building muscles.
They store excess weight in their thighs, buttocks and hips giving them a pear-shaped appearance. The best way for an endomorph to lose weight is through a combination of healthy eating and regular exercise.

Diet:

Start by cutting down carbs to only 30 percent of total daily calories. The other 70 percent should be divided into protein and good fats.

Workout:

Cardio is the best form of exercise because it ensures that the body does not revert to fat-storing stages.
They can also do high-intensity interval training and cross-training to build muscles.
Their main goal should not be to lose weight but to boost metabolism and prevent calories from turning into fat.

Mesomorph: This body type is generally considered the ideal body type. Individuals usually look lighter and have a more rectangular bone structure, longer limbs, thinner bones and a flatter ribcage.

A mesomorph has a natural tendency to stay fit and achieve muscle mass very easily.
They have more muscle than fat on their bodies and are not overweight or underweight.

Diet:

Just like ectomorphs, mesomorphs too can eat whatever they like without putting on weight, but the flip side here is that they may gain weight just as easily if they aren’t careful.
Because people with this body type have a lot to do with muscle, it stands to reason that they need a more protein-based diet that can help build and repair muscles.
They also need to consume a lot of fruits and vegetables rich in antioxidants and whole grains (quinoa, oats, etc.).

Workout:

Just because mesomorphs have a naturally muscular body doesn’t mean they don’t need to exercise. They do need training to stay lean. Alternating between weights and cardio would be the ideal workout for mesomorphs.