The Detrimental Effects of Diets on our Health

by Rebecca Cleary




With quarantine allowing more time for a large number of people up and down the country, there have been many trends involving getting fit or losing weight. I strongly believe that people shouldn’t feel as though they have to change the way they look or have an expectation to suddenly get fit over quarantine. Body images as portrayed with models, for example, don’t represent a realistic lifestyle. Models are paid to look the way they do; it is their livelihood. It is incredibly unlikely that anyone with a full time job, going to school or anything else that takes up time and energy will be able to look that way. However, for those that do want to change their bodies, dieting is an appealing option, but a potentially dangerous one.

By ‘dieting’, I am referring to restricting food (thus total calorie intake) or certain groups of food, with the goal of losing weight. However, restricting food that we eat has so many negative effects on our bodies.

Firstly, there is the effect on our hormones.

The first hormone is ghrelin. As ghrelin increases, our appetite also increases. When you calorie restrict, ghrelin increases, so your appetite will increase. Therefore, it is unlikely that you will stick to any diet because you’ll be hungry more of the time.


The second hormone, called Leptin, is released by our fat cells. It tells the brain when we’re satisfied and no longer want food. Studies have shown that when you restrict calories or lose weight, your leptin levels decrease. For example, at the end of the ‘Biggest Loser’ television programme, the levels of leptin in the people who’d lost weight were almost unreadable. When they followed up on these people 6 years later, they found that they’d regained almost all of their original weight. Therefore, when on a diet and afterwards, you will feel less satisfied when you eat and more hungry, so your goal is likely to be short lived.

The third hormone is cortisol, which is released when we are stressed. A study was conducted where mice were put on a calorie restrictive diet. Their cortisol levels were higher than the mice who hadn’t been put on the diet, and, translated to humans, are more likely to ‘binge’ or stress-eat.

So, hormonally, it is clear that those ‘fast result’ diets and high calorie restrictions are in no way beneficial for any sort of long term goals or general health.

But I want to focus on the negative impact of dieting on your mental and physical health.

Physically, by going on a diet, you are likely to lose weight. The basic principle that so many follow is having a calorie deficit (calories in < calories out).

This principle is right, and it will help people to achieve their goals. However, it can be dangerous.
The first, simple effect, is loss of weight, but not the weight that you want to lose. A very common misconception is that weight loss means success, but it doesn’t. In fact, weight has very little bearing on how fit or healthy we actually are. Yes, it is an indication, but regular scales don’t show any information on body fat percentage, for example. Body recomposition is what most people are actually aiming for, which is essentially losing fat and/or gaining muscle. Two people can be the same weight on the scales, but one can be mainly fat and the other mainly muscle. Weight loss includes losing muscle along with fat, so by restricting enough that you lose weight, you could end up losing muscle. This means that your body is ‘weaker’ and you are more likely to get injured or simply struggle with activity. This could further lead to complications and conditions, such as anorexia.

An incredibly important point is the danger of restricting energy intake. By restricting calories, you are restricting your energy intake. Thus, you are restricting energy for your body to carry out its functions. Our bodies prioritise movement. This means that, if you’re not providing enough energy to support regular functions along with ‘work’, such as general movement or exercise, then your body will prioritise the movement. Therefore, energy required for functions such as maintaining bone density, immunity, making red blood cells and the menstrual cycle will be thin on the ground. Heart health can also be negatively affected, as oestrogen levels will be lower, which leads to increased cholesterol production.

Diets can be incredibly detrimental to your mental health. By spending a significant amount of time focusing on food, people can develop obsessions over certain foods or calorie intake. This could ultimately lead to eating disorders. This focus on food can control people’s lives, impacting their behaviour, whether they attend social events and so many other aspects that others just don’t see.

Therefore, it is so important that, if someone feels as though getting fit or losing a little weight (or as is more specifically put, body recomposition) is something they want to do, then they should research and understand how to safely achieve long term goals instead of simply following the latest diet or just reducing what they eat. The message that you can lose a lot of weight in a short space of time is a damaging one, particularly to young people, and should not be encouraged. The quote that I think sums this up is from Totie Fields: “I’ve been on a diet for two weeks, and all I’ve lost is 14 days.”







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