Effects of caloric deficit/surplus and type of macronutrient on body composition

[monster405]

Hey Jordan,

First of all I want to say thanks for everything you and Barbell Medicine do. Your training programs and content have made me smarter about both my training and my health.

As for my question (or questions, rather), my friends were debating the effects of being in a caloric deficit/surplus AND the quality/type/source of macronutrient.

Friend A says that a change in one’s bodyweight is simply a function of caloric intake. In other words, a calorie deficit = weight loss, a calorie surplus = weight gain. As for body composition, friend A says that in a calorie deficit, with adequate protein intake and resistance training, one cannot gain fat. His argument being that a calorie deficit means an energy deficit. Gaining fat would mean one has an energy surplus. These two statements are contradicting. Friend A argues purely from a energy consumption point of view.

Friend B says that even in a calorie deficit, one can gain fat. The example he gives is the following hypothetical: Someone is in a calorie deficit. He eats adequate protein and trains adequately. The remaining calories all come from soft drinks. Friend B argues that the person in the hypothetical will lose muscle and gain fat (if I recall correctly, Friend B said that the muscle would “transform” into fat, whatever that means). In other words, Friend B said that the person’s body composition would worsen. Obviously no one is arguing that drinking that many calories worth of soft drinks is healthy. However, I wonder what would be the effects on body composition?

In summary, here are my following questions: 1. Are friend A and friend B even arguing about the same thing?
2. How does the body process different types of macronutrients (ie. different types of carbs)
3. Can someone gain fat in a calorie deficit? (excluding extreme cases)
4. What are your overall thoughts? I do realize this is a lot to ask for. If it takes too long to answer, I would appreciate if you could provide links towards sources where I could read more and hopefully answer these questions I have.

Thank you very much, doc.

[Jordan_Feigenbaum]

@monster405

Friend A says that a change in one’s bodyweight is simply a function of caloric intake.In other words, a calorie deficit = weight loss, a calorie surplus = weight gain. As for body composition, friend A says that in a calorie deficit, with adequate protein intake and resistance training, one cannot gain fat. His argument being that a calorie deficit means an energy deficit. Gaining fat would mean one has an energy surplus. These two statements are contradicting. Friend A argues purely from a energy consumption point of view.

Probably more appropriate to say weight change is a function of energy balance, which is true.

It is very unlikely that individuals will gain fat during a weight loss while also eating enough protein and resistance training, but if those two criteria were not being met, you could potentially gain fat and lose muscle- losing muscle faster than fat. That happens.

@monster405

Friend B said that the muscle would “transform” into fat, whatever that means).

This never happens.

@monster405

In other words, Friend B said that the person’s body composition would worsen. Obviously no one is arguing that drinking that many calories worth of soft drinks is healthy. However, I wonder what would be the effects on body composition?

If energy and protein intake are the same, pretty much nothing- though there is a risk of nutrient dilution when total sugar intake gets high, e.g. above 20’ish % of total daily energy intake.

@monster405

In summary, here are my following questions:

• Are friend A and friend B even arguing about the same thing?

I don’t know, I’d have to ask them more questions lol.

@monster405

• How does the body process different types of macronutrients (ie. different types of carbs)

Different types of carbohydrates are still carbohydrates. Save for fiber, they all end up as sugar in the gut. Higher fiber diets tend to be more satiating and have beneficial effects on a variety of health outcomes (and surrogates), but don’t seem to influence body composition directly.

@monster405

• Can someone gain fat in a calorie deficit? (excluding extreme cases)

It is unlikely, but possible.