4 Reasons Why Dieting Leads To Weight Gain


Many know that diets, which restrict calories, don’t work in the long run. However, many people are unaware of that dieting can increase the chances of gaining weight. When you embark on a reduced calorie diet, you send a signal to your body that less food is available. As a result, there are profound biological and mental changes that occur, which turn on the body’s fat storing mechanisms. 

First of all, let's make sure we're on the same page: Is gaining weight bad? NO. There is nothing wrong with gaining weight and no one should ever be shamed or feel ashamed of their weight.

The intention of this blog post is empower you to never diet again, as diets don't actually achieve the promised goal of long-term weight loss. Keep reading and you'll learn why. 

1. Your body wants to store fat

When you restrict calories, lipolytic enzymes decrease and lipogenic enzymes increase. In other words, fat burning enzymes decrease, whilst fat storing enzyme increase (1). This means that when you go on a diet to lose weight, your body will do what it can to hold onto every single fat cell it has.

2. Your leptin levels decrease

Leptin is a hormone which signals fullness. It normally rises following meals and when adequate calories are provided. The hormone tells the body to turn down feelings of hunger, whilst increasing metabolism. However, when calories are restricted, less leptin is produced (2). Less leptin means you’re less likely to feel full when it’s appropriate, for example after a big meal. So, what happens? You eat more. People who have been chronic dieters, often report that they just can’t stop eating and cannot feel full. In addition, leptin is only one of many other hormones which influence hunger and fullness. Other appetite-regulating hormones include ghrelin, insulin and neuropeptide YY (3). During calorie restriction, their levels also change, in order to make you seek out food and eat. Now you can understand how there’s no such thing as willpower when it comes to dieting! Your body and hormones will eventually take over in order to make you eat more, regardless of how much you try to abstain from food.

3. You become obsessed with food


People on calorie restricted diets often become obsessed with food and eating. You know that hangry feeling, when you’re so hungry you become irritable as fu** and all you can think of is stuffing your face with food? We’ve all been there and it’s a normal response to lack of food. But imagine having that feeling all the time. That’s exhausting. A good example of this is the Minnesota Starvation Study (4). Healthy men were recruited to the study, which examined the effects of calorie restriction on the body and mind. For 6 months they consumed approximately 1560 calories per day (a typical weight loss diet). The results of the study showed that the participants developed severe food preoccupation and reported that they could not stop thinking about food. They also exhibited urges to overeat and many engaged in extreme binge eating after the study.

Many people can relate to these cravings and maybe you can too. As soon as a diet starts and you have to limit your calories, that jar of chocolate spread in the cupboard or that box of ice cream in the freezer suddenly becomes a hundred times more tempting. And if you’ve been able to stay away from those mouth-watering foods during the diet, as soon as the diet is over, that ice cream box will be eaten within a millisecond. This is because calorie restriction also leads to cravings for high-calorie foods, overeating and bingeing in most people. Therefore, it’s common for people to gain more weight after restrictive diets.

The starvation study also showed that other effects of calorie restriction include depression, irritability, social withdrawal and isolation, emotional distress and decline in concentration. Calorie restriction is not fun! When we have more important to things to take care of, such as our families, friendships, hobbies and careers, we really don’t want to spend valuable time obsessing about food or even having our quality of life dramatically reduced. Considering that most diets fail and ultimately can lead to weight gain, it’s best to skip the torture of diets.

4. Your metabolism slows down

A six-year follow-up study of “The Biggest Loser” (an American weight loss TV show) showed that, compared to the participant's baseline, their metabolism decreased by almost 500 calories per day as a result of the dieting (5). Most of the participants also gained back a significant amount of their weight. The Minnesota Starvation Study also reported that the participants resting energy expenditure declined by up to 600 calories per day. In response to lack of calories, your body will do what it can to preserve energy!

Why does all of this happen?

Your body is clever and wants to keep you alive! Many people feel like they fail when they cannot sustain or lose weight on a diet. It’s not them failing, it’s the diet failing. DIETS DON'T WORK.

If you’re not eating enough, your body has no idea if you’re going to eat 1500 calories or 4000 calories today, tomorrow, next week or next month. It only knows that there’s lack of food right now. So it will kick start all of the fat storing mechanisms until you start eating enough again. Your body has these biological mechanisms in place so that you don’t starve to death. Thank your body for that! Yes, some people are able to restrict themselves for long periods of time, however, as mentioned, it leads to mental distress and it’s not worth the misery.

The number on your scale does not determine your worth and you don't have to go on any crazy restrictive diet to be healthy! In fact, I would encourage to throw away your scale and start practising self-love and acceptance, rather than self-hate (which the scale often triggers). 

“But, how the heck should we eat?”


If you feel a bit lost about what to do after reading this information, check out my blog post about how to have a healthy relationship with food here. It has practical tips about how to become the expert of your own body and your food choices, which you can start to use straight away. Also, if you like this article, please share it with others who you think could benefit from it!

If you’re obsessed with food, fed up with yoyo-dieting and body dissatisfaction, I can help also you break free from the burden of restriction. As a qualified Nutritionist and Intuitive Eating Coach, I teach clients how to heal their relationship with food and gain the confidence they need to know what to eat, how much and when. Click here for more information. 

I would also recommend to check out Laura Thomas’s podcast. She has some really interesting interviews with nutrition and health experts about ditching the diet mentality. They are truly refreshing to listen to!

Leave a comment below with which diets you’ve tried before and what you thought of them. Others may have had the same experience and we all benefit from sharing our stories. 

Eat and be merry, 

Vanessa x


Need food inspiration?

Look no further...

Your recipe book is here! Full of quick and delicious breakfast, lunch and dinner recipes, you will be blown away by how easy and satisfying a plant-based lifestyle can be!



1. Kern, P. A., Ong, J. M., Saffari, B., & Carty, J. (1990). The effects of weight loss on the activity and expression of adipose-tissue lipoprotein lipase in very obese humans. New England journal of medicine, 322(15), 1053-1059.

2. Cella, F., Adami, G. F., Giordano, G., & Cordera, R. (1999). Effects of dietary restriction on serum leptin concentration in obese women. International journal of obesity, 23(5), 494.

3. Bacon, Linda. Health At Every Size : the Surprising Truth about Your Weight. Dallas, TX :BenBella Books, 2010. Print.

4. Minnesota starvation study Keys, A., Brožek, J., Henschel, A., Mickelsen, O., & Taylor, H. L., The Biology of Human Starvation (2 volumes), University of Minnesota Press, 1950.

5. Fothergill, E., Guo, J., Howard, L., Kerns, J. C., Knuth, N. D., Brychta, R., ... & Hall, K. D. (2016). Persistent metabolic adaptation 6 years after “The Biggest Loser” competition. Obesity, 24(8), 1612-1619.