The truth behind health and weight: Is it time to stop dieting?

If you’ve got a history of dieting, it’s likely that you’ve been there: that panic that rises as you ‘lose willpower,’ break your diet rules, feel completely out of control around food, beat yourself up for it, and tell yourself that you’ll ‘start again on Monday.’ 


When Monday comes around the vicious cycle starts again until you’re at a point where you have no idea what to eat and when, feel anxious around food, and have no idea how to get out of it. Does this sound familiar? There’s a reason why dieting is so hard: we are going against our body’s natural instincts. This article looks at the science behind health and weight and whether dieting is really the healthy option.

Why do we diet?

Generally, diets are undertaken in the pursuit of weight loss. The pursuit of weight loss comes from the messaging which is thrown at us every day by diet culture.

Diet culture is everywhere. It’s defined as a system of beliefs that values the pursuit of thinness above health and wellbeing. As a culture, we are completely obsessed with how much we weigh and how we can lose ‘excess’ weight as quickly as possible. Diet culture is so embedded that it’s even in the health guidelines that we ‘should’ fit within a certain weight category. But does bodyweight actually have an effect on our health or has it been wrongly accused of doing us harm?

Health and weight

There are many problems when it comes to health and weight science. Health is a very complicated topic because there are many different factors affecting our health (mental as well as physical). To assume that someone is unhealthy because of a single factor such as body weight surely isn’t realistic, as health is more complicated than that. However, because diet culture is so strong and diet companies want to prove that their diets are worth buying, studies put a lot of significance on weight loss, when the association between weight and health isn’t proven, it’s just assumed.

Research into health and weight loss

Just like health, there are many factors that determine someone’s weight, which are very complicated. We can’t take everything published on weight research at face value. The first reason is because most studies in this area are short-term.

Participants generally take part in an intervention (usually a restrictive diet), along which time they lose weight, certain biomarkers of health improve (such as hypertension) and the dieting intervention is considered a success for improving health. However, in real life, we want to know what is best forlong-term health.

For these studies, there is hardly ever a long-term follow-up, or if there is, they find that the participants tended to regain the weight (77% after five years), some even ending up at a higher weight than when they started. Thus, dieting doesn’t work in the long term (if they did, you’d only ever have to diet once and never again).

Studies also tend to omit data on participants who dropped out (who couldn’t stick to the diet) which skews the results, presenting them as falsely positive.


Another thing to consider is the Body Mass Index (BMI). BMI is often used as an indication of where an individual’s weight ‘should’ be. It’s used alongside medical conditions and common guidelines at the GP.

Unknown to many, BMI was never intended for use on an individual level. It was developed by statistician Adolphe Quetelet in the 1800’s to be used in research at a population level.

It seems strange that the BMI has ended up as such a commonly used tool to measure health, as there are so many factors that contribute to health, and BMI is very simplistic. For example, it doesn’t take into account different body types.

Many sportspeople with high muscle mass will be shown as ‘unhealthy’ on the BMI scale, because it doesn’t take type of weight into account. It doesn’t make sense how we have ended up in a position where health status is based off what can only be described as a research tool. There isn’t a scientific basis to try and fit your body into a BMI category.

Can diets be harmful?

Weight cycling is common in chronic dieters. Weight cycling is when weight is constantly fluctuating, commonly due to the process of yo-yo dieting. Weight cycling has been proven to have a negative impact on health, as the body isn’t stable and is under constant stress. In fact, weight cycling has been associated with a higher risk of hypertension, chronic inflammation and even death! Ironically these are all conditions which being a higher bodyweight gets blamed on! On top of this, it has been shown that healthy behaviours alone (such as regular exercising) can improve health biomarkers regardless of any changes in weight. So maybe it’s time to recognise that it’s the physical act of dieting which causes harm to the body, not the body weight itself.

Another problem with dieting is that it messes with the metabolism. If you’re on a restrictive diet and ignoring your natural hunger cues, the body goes into survival mode. The body doesn’t recognise that you’re ‘dieting’ and just thinks it’s in starvation mode. The human body is very residual and will do anything to survive, so if it thinks there isn’t enough food, it will slow down the metabolism.

This means it will hang onto as much energy from every bit of food that you do eat. Which means thata) weight loss becomes harder and harder over time, no matter how much you restrict, andb) if you come off the diet and start eating ‘normally’ you’ll quickly regain the weight and probably end up at a higher weight than when you started. It’s very clever for our bodies to be able to do this – the fact that our biology kicks in to keep us going should tell you that dieting isn’t necessarily about what’s healthy.

Thirdly, dieting has a negative impact on the brain. The brain needs adequate fuel, particularly carbohydrates, to be able to concentrate and think clearly. If our body doesn’t have enough energy, the brain will become preoccupied with thinking about food. Have you ever been on a diet and had constant cravings all day long or struggled to concentrate because your mind drifts to food? This can lead to affecting your productivity in both your work and personal life.

Psychological effects

Dieting can have a huge negative impact on psychological health. One of the biggest risks which dieting poses is the risk of progression to an eating disorder. Even without reaching this point, dieting can cause a disordered relationship with food, with behaviours such as calorie counting, implementing rigid food rules, and skipping meals. This can cause a lot of anxiety and stress which can have a huge negative impact on quality of life. 

Are you ready to get off the diet train?

Are you convinced yet that dieting isn’t for you? If you’re concerned about your health, remember that you cannot tell how healthy someone is by looking at them. We all come from different cultures, backgrounds, lifestyles, genetics etc. We weren’t born to all be the same weight or to fit within a certain BMI category. Dieting to try and push your body into a size it isn’t supposed to be, could be causing harm in itself.

Where to go from here?

It can be a struggle to know where to start when trying to ditch the diets. If you’d like to read more about letting go of dieting, the books Anti-Diet by Christy Harrison, or Just Eat It by Laura Thomas PhD are a good place to start.

If you’re looking for support on improving your relationship with food, or even if you just want to look closer at the research behind this blog, why not book in with a non-diet nutritionist such as myself, for some extra support? I can promise that there will not be a diet plan in sight! 

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

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