Trying to lose weight by eating less? Fitness coach explains why an extreme calorie deficit may backfire

Trying to lose weight can be frustrating, especially when you're eating less, exercising regularly and doing everything by the book, yet the weighing scale refuses to cooperate. For some people, the problem may not be a lack of effort at all. It could be that they're cutting calories too aggressively.

“Undereating too much can actually make it harder to lose weight, over time,” says Chennai-based fitness coach Raj Ganpath. In a recent Instagram video, the founder of the Slow Burn Method and co-founder and head coach at Quad Fitness and author of Simple, Not Easy, explained why sometimes, eating too little can push the body in the opposite direction.

Stop ‘earning’ your calories – you’re actually putting on weight by not eating enough. And there are three reasons to that.

3 reasons excessive undereating may backfire

According to Raj, one of the biggest issues with very low calorie diets is that they can prompt strong hunger and cravings.

When people reduce their intake to 800, 900 or 1,000 calories a day, the body starts to respond to what it thinks is a lack of energy and nutrients. Those desires can build up over time and turn into overeating.

“The issue,” Raj says, “is that people remember the days they hardly ate but forget the times they may have overcompensated.”

When you eat very few calories, like 800, 900, 1,000 calories and create a huge calorie deficit, you are excessively undereating, and you’re depriving your body of energy and nutrients. So your body starts craving it. So invariably you are going to overeat, and you’re going to overeat excessively. But here’s the deal. You remember the undereating, but you don’t remember the extent of the overeating. And so you’re confused. You’re wondering why you’re not losing weight even though you’re hardly eating.

The second issue is much more subtle.

“If the body is not getting enough fuel, it naturally tries to conserve energy,” Raj says. Most people don’t see it happen, but it can show up in small ways throughout the day.

You can sit more.” Walk less. Fidget less. Even the smallest movements may become less frequent.

Your workouts might stay the same, but your overall daily activity might subtly drop.

“When you eat very little food, your body goes into an energy-conservation mode. And it does that by getting you to move less. Your exercise might be the same but you are moving less, you are moving your hands and legs less, you are sitting more, you are walking less during the day, even without your knowledge. All of this is very subtle but your body is doing this in an effort to protect you.”

Raj adds that eating too little for a prolonged period can also affect the basal metabolic rate (BMR).

BMR is the number of calories the body burns while at rest to maintain essential functions. When you’re eating very few calories and moving less throughout the day, the body adapts.

This means that the number of calories you burn at rest can also gradually decline.

“This can make it harder to stay in a calorie deficit and easier to fall into a calorie surplus,” Raj says.

“When you cut calories, when you move less, when you deprive your body, your basal metabolic rate goes down. Why? Your BMR adjusts to your activity and fueling. When both of these are very low, your BMR drops as well, which means it becomes very difficult for you to get into a calorie deficit and very easy for you to get into a calorie surplus. This is why when you overeat, you end up gaining weight very quickly.

For Raj, the takeaway is fairly straightforward.

So always remember, calorie restriction is necessary for weight loss, but undereating too much, which leads to extreme calorie restriction, is counterproductive. “What you need short term and long term is smart mindful eating.”

In other words, less can help you lose weight. However, eating far too little can create a completely different problem.