Building muscle to lose fat?

coderdan82 wrote: »

I've often heard these two statements:

"You should lift weights when trying to lose fat because increasing your muscle mass increases your metabolism so you end up burning more calories even when you're not doing anything."

and

"You cannot lose fat and build muscle at the same time because losing fat requires a caloric deficit whereas building muscle requires a caloric surplus"

Seems contradictory to me. Can anyone make sense of this?

The second statement is false. It is possible to build some muscle over the course of time while losing weight. It will be less than you would while eating at maintenance or above. Also, some populations (beginning lifters, overfat lifters, returning lifters) build more than others.

Additionally, while muscle does burn more calories than does fat, it's just about 6 calories per pound so it's not a huge increase. Usually the increase comes from increased activity levels in general. However, you should do some sort of resistance exercise in order to maintain and build strength and muscle and strong bones.

Lift during a deficit to maintain muscle and body composition, not to build muscle. Yes, muscle burns more calories than fat while at rest, but to build muscle (not talking about newbie gains), you need to be at a caloric surplus. However, you can maintain a good portion of your muscles while cutting by lifting. Your muscles will look bigger when you start to get rid of the fat around them...this makes it look like you may be gaining muscle.

If you've ever seen someone lose a significant amount of weight doing only calorie restriction and cardio, they look more frail and have no muscle, because they lost muscle mass as well as fat mass.

Lift heavy and tell your body you're still using those muscles.

...or so I'm lead to believe.

The first statement is true but you need to consider by how much and if it's actually significant.
Muscles burning 6 cals/ lb / day at rest compared to fat burning 2 cals / lb / day I would say would be insignificant as a weight loss method.
The saying is a throwback to earlier times when it was thought muscle burned a huge amount of calories.

The second statement is simply false. Absolute statements should be viewed with scepticism and are frequently parroted by people without thought or understanding,
Muscle can be gained at maintenance or at a caloric deficit appropriate to an individual's unique circumstances.
A caloric surplus may well be optimal for muscle growth but it's not an absolute requirement.
Gaining muscle and losing fat simultaneously used just to be called "getting in shape" and is a totally normal expectation for someone training effectively while eating around maintenance calories - nowadays it is often called recomp.