By changing the environment around you.
Our bodies adapt to the changing environments around us. Some adaptations like skin tone and body size (which regulate against the effects of the sun and heat production/dissipation respectively), take thousands of years.
Others, like our body composition, are short term adaptations and only take months.
When humans first ventured north out of Africa and into Europe, they found themselves in an environment that was new. The sun was less intense and was out for less of the day too. Over time their skin started to lighten since lighter skin absorbs UV light better which is needed to make vitamin D.
Their bodies also got bigger because a bigger body holds in more heat (smaller surface area ratio to overall body volume). Don’t believe me? Just ask any married couple who the furnace is in bed every night. Right, it’s the dude. See, you don’t even need science for this.
The point is that with these long term adaptations the environment changed and people’s bodies naturally changed too. Luckily, we don’t have to wait millennia to lose weight.
Being fat adapted simply means that your body is used to burning fat as it’s main source of fuel and uses that most often. Like a runner who has more red blood cells and whose heart and muscles have more capillaries, the fat adapted person has physiological adaptations in place so that the body regularly burns fat and uses ketones for energy instead of glucose.
If that’s a bit too out there try thinking of the person who drinks regularly. After changing his internal environment by filling his body with alcohol everyday, he adapts to it and is able to drink more and more without getting drunk. His body (specifically his liver) becomes better at processing it and so it’s a different liver than other people’s liver and he can now, “drink you under the table.”
CHANGING THE ENVIRONMENT
So how do we change our environment to become lean and mean. We do it by taking away the fuel source that our body is used to (carbs). This forces the body to use another source of fuel instead which happens to be fat.
Fat from our bodies and fat from our diet.
Like the runner who’s physiology has changed, our physiology will change too, creating fat-burning, metabolic pathways that become more and more entrenched in us. The longer we keep it up, the more it becomes the default way we burn energy.
What is basically boils down to is eating a low carb diet consistently over a long period of time.
The consistency is the key. You can fall off the wagon and have a cheat day here and there so long as you are eating low carb most of the time. As long as your body is interacting with the newer environment most of the time.
High intensity exercise, intermittent fasting and eating less in general all help, but the easiest and most efficient way to get there is a low carb diet.
Change your environment, become fat adapted and watch it melt off.