The field of nutrition is notorious for having conflicting ideas, opinions, and science. This has resulted in mass confusion about what to eat, how much to eat and when to eat it, in order to be healthy. This Nutrition Myth series aims to dispel some common myths around nutrition, whilst providing some simple universal tips for people to follow.

The Nutrition Myth series will address:

  1. Do you need to count calories?
  2. What is the best diet?
  3. Why do people regain weight after weight loss?

Why do people regain weight after weight loss?

It’s the classic weight loss story, all too common. You lose weight after some form of dieting. Then the weight loss plateaus. After some time, you’re back to your original weight. Why is sustainable weight loss so difficult?

The myth is that people put weight back on because they got lazy, undisciplined and fell off the wagon. Or that it’s simply a matter of reducing your calories even further. The truth is, when we lose weight, our bodies have a number of ways to encourage us to put the weight back on!

As we restrict calories, our body senses we’re not getting as much food as usual. It doesn’t know we’re dieting and assumes we’re in an environment without much food availability. If our energy intake (what you eat) has gone down, the body responds by:

  1. Decreasing your energy expenditure (how much energy you burn)
  2. Encouraging you to increase your energy intake

It does this with a variety of mechanisms:

  • Our basal metabolic rate decreases. This is how many calories your body burns just to keep you alive.
  • Our hormones also change, which affects our appetite
  • Ghrelin levels (the “hungry hormone”) increases and the hormones that make you feel full and satiated after a meal decrease.

So let’s say your body normally requires 2,000 calories in a day. You start eating 1,500 calories every day, and you begin to lose weight. Your body senses your weight loss, and lowers your metabolic rate, so now your body only burns 1,500 calories a day. The weight loss plateaus. Not only that, you are now hungrier than ever. Eventually, you start eating more and the weight starts creeping up again.

So we are designed to regain weight! It was a survival mechanism our ancestors evolved during times of low food availability. This may seem like a hopeless situation, if our very bodies are against us, but there are things you can do. Exercise has been shown to increase your metabolic rate and improve your appetite signalling. Notice that this is the opposite of the changes your body makes during calorie restriction. Studies also show that people who exercise regularly are better at matching how much they eat to how many calories they need, making them less likely to overeat.

What’s more important than going on short term restrictive diets is to focus on long term and sustainable changes to your nutrition and lifestyle. Focus more on what you are eating rather than how much. Focus on healthy foods that fill you up, rather than starving yourself for weeks. If you are still not losing weight, check your diet to see if there are any foods that might be the cause (for example, nuts are healthy but still high in calories). Take your time and focus on feeling good rather than what the scales say.

This blog concludes our Nutrition Myth series. We hope you’ve enjoyed it!

Is there any nutrition/diet content you’d like us to discuss in a future blog post? Or perhaps you have some questions from this Nutrition Myth series? Get in contact and let us know.