We’ve all heard this a million times, and it seems to make logical sense. If we go too long without eating, wouldn’t our body think it’s being starved and drastically reduce its metabolic speed? In order to better deal with the future starvation mode, wouldn’t it increase the rate at which it stores fat once we actually do eat? Regardless of how much it might seem theoretically plausible, it’s not true.
Fasting Put Your Body into Starvation Mode
Lets us know when fasting put your body in starvation mode:
FASTING DOESN’T NEGATIVELY AFFECT YOUR METABOLISM
The metabolic rate didn’t decline until 60 hours of fasting and the reduction was a mere 8% of 106. In fact, research has demonstrated that the metabolism actually speeds up after 36-48 hours of fasting107, 108. The true starvation in the eyes of the body occurs after about 3 days of not eating, at which point the primary source of energy becomes the breakdown of proteins and the biggest source of protein is muscle.
Until then it relies on body fat and glycogen stores in the liver and muscles for its energy, nothing more than routine biological functioning. Once it has to begin breaking down proteins for energy, however, the body knows its survival imperiled, and that is when the real starvation mode begins.
This makes sense from an evolutionary perspective. If we haven’t eaten in quite some time, what does our body want us to do? Go find food, of course. And how does it stimulate us to do that? By increasing the production of two chemicals called adrenaline and noradrenaline, which sharpen our minds and make us want to go move around.
They also increase our basal metabolic rate, the minimal amount of calories you burn at absolute rest. (exercise elevates these chemicals as well.) And what happens when we lose muscle? We become physically weaker, our metabolism slows down, we become more likely to succumb to disease, and eventually, we die (usually from a heart attack).
THE HEALTH BENEFITS OF FASTING
A growing body of evidence is demonstrating that fasting has various health benefits. Studies have shown that fasting increases insulin sensitivity, stress resistance, fat oxidation, and lifespan and reduces the risk of diseases. Yes, you read that right: Relatively long periods of fasting (16–24 hours) actually improve your health and help you burn more fat without any worries of the body obsessively storing every calorie you eat after the fast.
There are dietary strategies built around this research, and they are known as intermittent fasting routines. Such protocols entail splitting up your days into fasting and feeding periods, usually calling for 16–20 hours of fasting and 4–8-hour “feeding windows.” You eat your entire day’s worth of calories during these feeding periods, which requires large meals, especially if you’re lifting weights. You should also know that intermittent fasting while exercising regularly requires proper meal and workout timing if you’re to make optimal gains.
I won’t go into all the details here, but if you’re interested in following this style of dieting, I recommend you read my blog post on it and searching for “intermittent fasting.” Personally, I don’t like having to eat large (1,000+ calories) meals due to the uncomfortable fullness, as well as the ensuing lethargy caused by a hormone called cholecystokinin that is released when you eat protein and fat.
The key takeaway from this chapter is that you can eat infrequently if that’s how you like to do it or have to due to schedule hiccups. Only two meals need be set in stone: your pre- and post-workout meals. Your pre-workout meal should contain about 30 grams of protein and carbohydrates, and your post-workout meal should contain about the same amount of protein and between 30–40% of your total daily carbs.
You can even work in a planned fast once or twice per week to reap some of its benefits. I will occasionally do this by simply skipping breakfast on a day that I’m not lifting (I lift early in the morning) and eating my first meal after about 12–14 hours of fasting.
MYTH: CAN’T DO CARDIO IF WHEN YOU WANT TO GAIN WEIGHT