The rise of the diet industry and its correlation

with the rise of global obesity 

Written by Louise Mercieca - 10th January 2022


There are many things that are associated with the month of January; cold weather, dark nights, huge credit card bills and, of course, New Years’ Resolutions! One of the most common resolutions is to go on a diet. This isn’t surprising given the excess we usually succumb to over the festive period. But, given their popularity, the big question is: do diets really work?

There are many versions of diets, some sensible, some frankly dangerous, but how did it all start? 

Dieting all began in the 1970s when we started to see some big changes in the way we shopped, cooked, and ate food. Our food landscape really began to change as we were able to opt for a more convenient way of shopping and eating, but this was also when we saw the first flurry of diet foods and diet products. This followed a health scare in America from the previous decade where there had been a rise in deaths caused by Coronary-Heart-Disease (CHD). The culprit was deemed to be dietary fat. Many foods became demonised, and the low-fat industry was born. This particular view of the nutritional influence of fat was largely upheld from roughly 1974-2014.

Pure, white and deadly

There was some opposition to this view; John Yudkin published his book, Pure, White and Deadly in 1972. At the time he was a British nutritionist and the former chair of nutrition at Queen Elizabeth College, London. This was the first ever publication to link sugar with obesity and heart disease.  However, unfortunately, no one took this view seriously until around the year 2000 when some cohort studies started, once again making the links with sugar consumption and risk factors for CHD, obesity, and other conditions.

If only a small fraction of what is already known about the effects of sugar were to be revealed in relation to any other material used as a food additive, that material would promptly be banned”.

John Yudkin – Pure, White and Deadly - why sugar is killing us and what we can do to stop it

Eliminating Fat & the increase in sugar

Fat is, and always will be an essential part of our diet. Back in the 1970’s, the only real types of fats in our food supply were natural fats such as butter, cheese and meat, and the ‘healthier’ fats, oily fish, avocado, nuts, and seeds (now we have many more artificial fats in our food chain, which are much more damaging to health). In demonising fats in favour of everything low-fat, all fats were excluded including many that our body needs (Essential Fatty Acids). One fact that diets fail to mention is that the body can metabolise fat from real foods. Fat is in fact a valuable resource for energy and once used does not get stored as adipose tissue. The notion of ‘fat being bad’ is still a real concern for many people who are put-off eating any dietary fat, including ‘healthy fats’ because they think they will put on weight. But what did we start eating more of?

The missing link

What happens when we eliminate one food group and create another? A real lack of flavour! To add flavour to otherwise plain and tasteless diet foods, many ingredients needed to be added.  To enhance flavour to low fat products, one ingredient above all others increased, that ingredient was sugar.  Despite the concerns raised by John Yudkin, from the mid 70’s onwards, sugar consumption increased significantly, especially in America where they also introduced High Fructose Corn Syrup. Whilst everyone was tucking into low-fat foods and following the health information provided to them, obesity rates were gradually rising. Worldwide, global obesity has tripled since 1975 so, from that perspective, it’s not looking like diets really work at all!

Diets and Global Obesity 

One interesting observation about diets is the whole time we have had a diet industry (an industry consisting of diet clubs, books, food products and, in more recent years, on-line ‘solutions’), we have also had a growing obesity crisis, and I don’t use the word crisis lightly, as obesity is a condition that brings with it, a host of comorbidities including Type 2 Diabetes.

Key facts from the World Health Organisation on Obesity statistics

  • Worldwide obesity has nearly tripled since 1975.
  • In 2016, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 650 million were obese.
  • 39% of adults aged 18 years and over were overweight in 2016, and 13% were obese.
  • Most of the world's population live in countries where overweight and obesity kills more people than underweight.
  • 39 million children under the age of 5 were overweight or obese in 2020.
  • Over 340 million children and adolescents aged 5-19 were overweight or obese in 2016.
  • Obesity is preventable.

Obesity, can we say it?

Due to the way in which obesity is often portrayed in the media, it has gained a rather negative image.  One which causes a divide and a lot of misunderstanding. An example of this is that obesity is simply caused by ‘greed and laziness’ and can be solved by ‘moving more and eating less’. Neither of these are the case but people are often afraid to mention the word for fear of causing offence. We need to treat obesity as a medical condition and not something to be ashamed of.

Obesity is a very complicated combination of issues: -

  • Obesity is a medical condition
  • Obesity is an extremely complicated mix of issues, emotional and physical 
  • Obesity is not just to do with what you eat
  • Obesity has many co-morbidities 

According to the NHS by 2030;

50% of the UK will be classified as obese

So, do we all need to go on a diet? No. Obesity is a complicated issue. It is actually many issues, and restricting calories does not address these issues. 

Dieting and obesity

There are many reasons why dieting contributes to an ever-increasing obese population: -

  • There’s still a lot of sugar in diet products, but they are now accompanied by artificial sweeteners.
  • There is a real lack of nutrients in most diet products - it is often the little things that make the biggest difference and vitamins and minerals support fat metabolism.
  • Artificial ingredients in many diet products are harmful to the gut microbiome – the gut microbiome is an essential part of fat metabolism and blood sugar regulation.
  • Fats are a useful energy source to the body and can make us feel full.  Eliminating them can lead to over-eating on less nutritious food without ever feeling full.
  • Counting calories is pointless if you don’t consider what is in the calories.
  • Dieting can lead to feelings of guilt over food indulgence, which is damaging to mental health and self-esteem - this can often lead to emotional eating.
  • Weighing yourself is damaging to self-esteem and counterproductive to fat metabolism, as the scales don’t tell you your body composition, only your weight.
  • Diet clubs can damage mental health as everyone is unique and will only lose weight in a way that suits them individually. There is definitely no ‘one-size fits all’ solution.
  • Public weigh in events at diet clubs are very damaging to self-esteem.
  • Diet related guilt and self-esteem issues can often lead to emotional eating.
  • Diets damage food relationships, making people see ‘good’ food and ‘bad’ food or feeling ‘naughty’.
  • Diets lead people to punish themselves via food restriction, not nurture themselves via food choices.
  • Stress (often brought on by the diet itself) increases the stress hormone Cortisol, which increases abdominal fat, so worrying about your diet can actually make you store more fat.
  • Restricting a food makes you want it more.

This is not an exhaustive list, as there are many more factors, but fundamentally the problem with diets is that they only look at what is on your plate. What we need to do is to look at what drives the food decision to choose that food. This could be a combination of emotional eating, food habits, food addictions and/or misinformation on food choices. Educating ourselves on nutrition and fat metabolism is key to then actually losing weight, and more importantly, maintaining a healthy weight, whilst not damaging our relationship with food.

If diets worked, then we wouldn’t have an obesity epidemic. In fact, during a webinar I attended recently on Public Health, Nutrition Professor David Katz stated that there had been a slow pandemic happening throughout the western world, long before the Covid-19 pandemic. This pandemic was due to the fact that: -

Diet is now the number one predictor of all cause mortality surpassing tobacco”.

To put it another way, our food environment has changed and is causing poor diet to be the number one cause of premature death around the world.  When we factor in the fact that for 40 years’ we followed a health trend that actually caused obesity despite being launched as a low-fat health initiative, it’s hardly surprising that everyone is a bit confused and doesn’t truly understand why the food we eat is making us ill.  

We are heading towards a future where obesity is normalised, as it is so common place, but no matter how common it is, obesity is a serious health concern, one which causes a deterioration in the quality of life and life expectancy.  We cannot expect any fundamental changes from the global food-industry overnight, if anything in the last 20 years our food has got much worse with the rise in Ultra Processed Foods (UPF’s).  Without any significant change, we need to be the change, to understand for ourselves what we are eating, what we are feeding our children and how this food has the potential to shape all of our future health.

Reference sources

Adult Obesity: Is Childhood sugar intake in the 1970’s to blame?

Fat, Sugar, Whole Grains and Heart Disease: 50 Years of Confusion 

Pure, white and deadly -John Yudkin – 1972

Why We Got Fatter During the Fat-Free Food Boom

A Sugar Infusion in 1970s Food May Have Led to Obesity Crisis Today 




Louise Mercieca is a Nutritional Therapist, Consultant, Author, Presenter on Early Years TV Food, and Founder of The Health Kick, a business driven by the mission of providing understandable, practical nutritional advice, in a world driven by diet culture and convenience eating. Louise is influential in early-years health, making an impact that can influence the next generation’s eating habits. She is the author of ‘How Food Shapes Your Child’ and is hugely passionate about spreading the message that kids can make healthy food choices.