Those Who Are Overweight Had a Higher Basal Metabolism

It is generally accepted (in Japan) that if you build muscle through exercise and increase your basal metabolism, you will be less likely to gain weight.

This is because the calories expended by basal metabolism account for sixty to seventy percent of the total caloric expenditure in a day. (Note: Daily caloric expenditure varies depending on the intensity of the work.)

I'm very thin, so I was skeptical about this, but several years ago there was a program on NHK (Japan's national broadcaster, more reliable than commercial broadcasters) that was helpful!

muscular vs chubby
【Tameshite Gatten(It means “try and get it.”) – I lost weight so easily -】(2011)

When the basal metabolism of the team A (slim and muscular) and the team B (chubby:heavier than A) were examined by a research institute that can precisely measure the basal metabolism, it found that team B had a higher basal metabolism.

In fact, the brain and internal organs (heart and liver, etc.) account for the largest portion of basal metabolism, while muscles account for only twenty percent.

If you want to expend calories of fifty grams of rice (about eighty kcal), the amount of muscle you need is equivalent to about two-point-eight kilograms of meat. 

It seems that you need a lot of muscle in order to lose weight, but this would make you muscle-bound.

In the first place, basal metabolism is the energy expenditure when “you are at rest," so it doesn't seem to have much to do with building muscle.

♦To begin with, if you look up basal metabolism, the general method of calculation is "[basal metabolic standard] x [body weight]" (from wikipedia).

(Basal metabolic standard value)

♦The other method of calculation is called HBE (Harris-Benedict Equation).
[Basal metabolism] (kcal/day)= 66.473+13.7516 [w]+5.0033 [h]-6.7550 [a]
w=weight (kg), h=high (cm), a=age

As you can see from both of these formulas, if you are the same age,
your basal metabolism will be higher if you are heavier (fatter). It's only natural, since their bodies are that much bigger, they must use more energy.

Of course, if you gain more muscle, you may be able to slightly increase these baseline values, but there is not enough evidence to say that you are thin/lean because your basal metabolism is high.

"Since losing weight reduces total energy expenditure, many obese people assume that they have a slow metabolism, but the opposite has proved to be true. Lean subjects had a mean total energy expenditure of 2404 calories, while the obese had a mean total energy expenditure of 3244 calories, despite spending less time exercising.

The obese body was not trying to gain weight. It was trying to lose it by burning off the excess energy. So then, why are the obese... obese?"

(The Obesity Code, Jason Fung, 2016, Page 62)