I first came across this 11 years ago, when dieting on the internet had really taken off. Not only that, I also heard podcasts talking about eating more to lose weight, which was very confusing to me at the time because I thought that calories controlled weight loss. So what was actually going on here?

What is it actually possible that people who are under 1000 calories a day somehow stopped losing weight because their body shutdown and their metabolism slowed too much? Certainly seems like a convincing argument, so I decided to look into it before working in the fitness field and telling clients random stuff that I had heard that seem convincing. Because if this was true then it could radically transform the fitness and health industry as a whole.

In my head I was comparing the pictures that ones sees from World War II of the survivors of Auschwitz, who were extremely thin versus images of a modern overweight person struggling to lose weight. It was almost as if they seemed to work by two different sets of rules.

The Argument

The argument I saw for this was that as one restricts calories and loses weight the metabolism adjusts. So far so good. Once you reach a certain low point, it essentially crashes out and stops you from losing anymore weight or makes it extremely challenging.

Suddenly people are losing weight on meals that seem much bigger than meals they were previously stuck on. Sometimes they were even gaining weight on very small meals. We're going to examine this more carefully in a moment.

This was then followed up by a reverse diet, during which one gradually increases calorie intake to give the metabolism time adjust to the increase without suddenly gaining a large amount of weight, or more precisely fat. That would obviously be counter-productive.

The exact method in fact, would be to increase calories by 50 every week and then examine whether body weight increased or not.

In Week 1 calories might increase by 50 but there would be no gain in weight.

In Week 2 one would simply repeat the same method as in Week 1 and so on, until in Week 4 for example weight might increase. At this point one would leave calories as they are to give their metabolism time to adjust.

The Result

After thinking about this for a while and listening to a variety of podcasts, I finally turning to the research and spoke to people who had been in the industry for over 30 years. I figured out what was happening.

Elements of this approach were good or even useful but other parts were simply mistakes. They were mistakes which were used to market something that wasn’t true. Yet, your average Joe would not know any better.

What was really happening was that these big meals often included more protein and vegetables, more specifically lean protein. The result of this was that the meals visually appeared bigger but from a calorie perspective where actually LOWER than what the people had previously been eating.

This was why it seemed as if they were eating more and losing more at the same time, going against all the rules of nature.

You might be wondering but how can this be true if the person has calculated how much they are eating and reported it to be under 1000 cal. There is a simple answer to this which, since then, I have seen with every person and client claiming the same. This is known as under reporting, which is often accidentally done. I don't believe people purposefully under report the calories however it can be tricky for everyone doesn't have much experience.

It's very common to forget things like snacks, drinks, oils and dressings. These are all things that can be extremely high in calories and add anywhere from 1000 to 2000 a day. Here is an example of some commonly consumed healthy foods that skyrocket calorie intake.

So really all that is happening is that you are eating less but you believe that you eat more.

What about the second element regarding reverse dieting starting or slowing of the metabolism?

Yes it's true, your metabolism will “slow” Compare to what it was before you lost weight but then you are also a smaller person who requires fewer calories to look the way they do now. If you are have more body fat then obviously you will have to eat more to stay the same overweight person.

So even this metabolic adaptation is to a large extent down to the fact that you are just a smaller person in terms of width.

Having said that it is worth taking breaks from dieting and reversing it slowly as it can, to an extent, increase metabolism. In fact what happens, as you eat more, is that you start to expend more energy subconsciously. Now the body isn't trying to preserve energy any longer. So you will blink more, move your arms more when you're trying to explain something to someone, move your head more when you're looking at something and generally be more active.

There is no magic to this, it's simple adaptation and survival. So if you're ever stuck and not losing weight it's because you're eating enough. In turn your body can maintain its current weight and looks. To solve this issue you just have to eat a bit less, as the body takes the missing fuel from your fat.

I have an avid interest in all things human body and as such help people lose weight. Other interests include language learning and the science behind longevity