Does Britain need to go on a diet?

8 April 2021

Public Health England (PHE) now wants the country to go on a diet. PHE wants the portion size of some of Britain’s most popular foods to be reduced. They have also asked the food industry to opt for healthier ingredients and the public to choose low calorie options. 13 different food items, which are responsible for 20% of the calorie intake of children, will be targeted. The popular foods which are targeted by PHE to reduce calories and portion size include savoury biscuits, crackers, special bread such as ciabatta with olives, cooking sauces and dressings, crisps and savoury sauces, egg products, potato products, meat products, pasta, rice, noodles, ready meals, pizza, sandwiches and soups. The list includes nearly every food we consume!

The Chief Executive of PHE, Duncan Selbie says “children and adults routinely eat too many calories and it’s why so many are overweight or obese”. This is certainly not rocket science as everybody, including people with a weight problem, knows that you can become overweight or obese by eating excess calories.

Nearly two-thirds of the adult population in England is overweight or obese. It’s estimated that the average adult has 200-300 more calories than they need every day. There is information overload about cutting calories everywhere. You are sure to find a television channel talking about obesity at any given time. Social media, doctor’s surgeries, newspapers and magazines have articles about reducing calories and losing weight. All of this is topped off with the ever growing promotion of fad diet plans and quick fixes. And now the time has come where we are witnessing a diet advertisement for the whole country!

The 400-600-600 diet … will it work? Let us first discuss dieting at the individual level.

Why don’t diets work?

A Mintel report from 2014 revealed that a shocking 55% of Britons went on a diet in an attempt to lose weight in the previous year. Since this report Britain’s children have become heavier and even more people are trying out diets. This clearly shows that dieting has not helped Britain.

Most people who go on a diet regain their lost weight. Several studies have shown that dieting triggers compensatory neurobiological adaptations within the body. Lowering of your basal metabolic rate following dieting is one of the predominant reasons for weight regain. There is epidemiologic evidence that demonstrates weight regain occurs even after 24 months. When you diet, there are several metabolic changes which occur in the body including alteration in secretion of the hunger hormone ghrelin and fullness hormone leptin. There is also ample evidence of changes occurring in the brain to help the body adapt to the calorie restriction.

No wonder the diet industry has been thriving and it is hardly a surprise why people move from one diet to another. In an article in the International Journal of Obesity titled “Physiological adaptations to weight loss and factors favouring weight regain”, the author Greenway states that obesity is the result of flawed food intake behaviour.

People know that you have to eat less and losing weight not only improves body image but also has health benefits. Royal college of physician guidelines shows that losing even 10% of your body weight has significant benefits including reducing the incidence of Type 2 Diabetes, certain cancers and lowering blood pressure.

So, why can’t we continue to lose weight and why is it so hard to avoid calorie dense food? The reason for consuming energy dense food is multifactorial.

What is the real cause of weight gain?

There are several reasons why you prefer energy dense food, which in turn leads to weight gain. We are supposed to eat to provide energy to the body, but these days we eat for reasons other than true hunger. Some of the reasons may be familiar to you: it is time to eat, I’m at a party or social event, I am bored and tired, I am upset, I am happy, I am lonely, I had a disturbed night, I am stressed and many more.

Hedonic hunger or “eating for pleasure” is one of the main reasons we eat these days. If this is not tackled, we will continue to be forced to eat more. Fatty and sugary food triggers chemicals in the brain, which makes you feel good. In the modern world every one of us are faced with challenging situations as a result of which we turn to food for comfort. All the knowledge about healthy eating gets washed away when the sensation for hedonic hunger creeps in. When you are in any of the above situations you need a reward to perk you up. Drugs, alcohol and smoking are not usually socially acceptable at any time of the day. However, eating junk food is pretty commonplace and hence we go for it without a second thought.

If the calorie content of food is reduced as suggested by PHE, in the short term we will try and find a high calorie food which satisfies our hedonic hunger. Free school meals were a very good idea. However not every school provided healthy meals. Moreover this was just one meal of the day (lunch) and the rest of the meals and snacks dictated the overall health of a child. Similarly adapting a knee jerk reflex on cutting calories will not help improve the nation’s health in the short term. A holistic approach targeting all the factors which promote weight gain should be addressed and a long term view should be undertaken by the decision makers.

Surely cutting calories will help…

One needs to understand our gene pool has not changed in a million years; it is how our genes interact with the environment which has changed. Obesity is a collateral damage which we have incurred with modernisation. Offshoot of modernisation contributes to stress, poor sleep and relationship problems. We now know that there are several factors which forces us to eat more, prefer high calorie food and also alter our metabolism. We need to deal with the underlying issues which drive us to eat high calorie food. Recent research shows that poor sleep, altered thermoregulation, abnormal gut microbiome, stress hormones, low self-esteem, relationship problems, medications, endocrine problems, disordered body clock and many more factors force us to eat more.

Let us just take one of the factors mentioned above, which is poor sleep hygiene. We now know that our sleep is considerably reduced and the quality of sleep in the last two decades has worsened. Professor Matthew Walker, in his book “Why we sleep”, has described in detail how poor sleep hygiene can result in weight gain. Reduced sleep duration and poor quality of sleep stimulates the sympathetic nervous system and promotes increased stress hormones, which in turn has an impact on the hunger hormone ghrelin and fullness hormone leptin. People who work in shifts or have sleep apnoea are more prone to weight gain. Sleep is also disturbed as we spend more time using screens such as TVs, laptops and mobile phones, especially late at night. The light emitted from digital devices has a higher concentration of blue light than natural light. Blue light affects levels of the sleep-inducing hormone melatonin and interferes with the body’s biological clock. This group of people would struggle to stick to a healthy eating plan.

So, you have someone who is struggling with sleep and PHE asks them to go on a diet. Do you think he or she is going to follow the plan and even if they do, how long will they stick to the plan of having low calories, when their body is pushing them to eat more. Let us assume they do follow the reduced calorie meal, but the poor sleep hygiene and its impact on metabolism will prevent them from pursuing the plan and eventually result in failure.

Failing on a diet generates further problems including low self-esteem, under confidence and the lack of drive to try any other weight loss plan. In many cases it becomes considerably harder to lose weight on your second, third and future attempts (more on that in another article). Here we have merely described one factor, other than calorie restriction, which determines how we eat and lose weight. It’s truly hard to understand how complex obesity can really be.

More than 50% of the people in Britain are either overweight or obese and a significant proportion of them would have already tried some sort of diet. People who have been on a diet have lowered their resting energy expenditure (basal metabolic rate or BMR). Therefore this slight reduction in calories as proposed by PHE will not benefit a significant proportion of the adult population who have been through diets previously.

So, how can Britain lose weight and keep it off?

The term “dieting” has become associated with bad connotations. In the first instance we need to move away from dieting and encourage people to choose and adapt a healthy lifestyle. The term lifestyle does not encompass food and activity alone but rather it includes a whole raft of factors, which determine energy consumption and expenditure. It’s important to note that just like telling people to “eat less” doesn’t work, it’s also futile to simply tell an overweight or obese person that “moving more” will solve their all their problems.

Public Health England’s drive to reduce calorie consumption by 20% by 2024 is an excellent start. However, advising the food industry to reduce calories and people to consume fewer calories is targeting the final step which leads to weight gain. We already know that we need to eat less. The most effective and lasting solution would be to address the underlying issues which drive people to consume high calorie food in the first place. And that, is an entirely different ball game.

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