Low-carb or high carb diet: What I want you to know about the ‘healthiest diet’, as an NHS Doctor A study found consuming a diet that is either very high or very low in carbohydrates is associated with a shorter life expectancy

Today’s research published in Lancet Public Health sheds interesting new light on what may constitute the healthiest diet.

Researchers found consuming a diet that is either very high or very low in carbohydrates is associated with a shorter life expectancy, with a “sweet spot” found somewhere in the middle at 50 per cent of calories.

But good science requires putting the findings in the context of the best available up to date totality of evidence.

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A few weeks ago a robust systematic review carried out by some leading independent researchers from the prestigious Cochrane Collaboration and an eminent Professor of diabetes revealed that when comparing all randomised trials of low fat versus low carbohydrate diets for type 2 diabetes, the latter was significantly more effective in the short term and marginally better in the long term for controlling blood glucose and improving all cardiovascular risk factors.

‘Consuming refined carbohydrates in excess, from foods such as white rice, bread, pasta and of course sugar is harmful’

What is crucial to understand is that consuming refined carbohydrates in excess, from foods such as white rice, bread, pasta and of course sugar is harmful. Starchy foods provide very little nutrition, are not particularly satiating and rapidly raise blood glucose which is particularly detrimental to those with diabetes. If you don’t burn the energy rapidly from exercise it will quickly get converted to fat.

So what does a healthy diet involve?

Last year the largest observational study on diet and health in the world, PURE, also published in the Lancet also revealed a high carbohydrate diet was associated with increasing death rates. Conversely, a higher consumption of saturated fat from foods such as butter and cheese was found to correlate with less likelihood of stroke and death. This has been reinforced by another study on full-fat dairy published a few months ago suggesting the same.

But what does this all mean for the general public? What should you be eating if you want to live a healthy life for as long as possible? From my own analysis of the research in this area, which is detailed in my book The Pioppi Diet ( based on one of the world’s healthiest villages, what I personally follow and what I advise my patients to) is to avoid as much as possible starchy carbohydrates, cut out sugar and base one’s meals on extra virgin olive oil, a handful of nuts daily, oily fish at least three times per week, eat plenty of vegetables and low sugar fruits. The Deputy leader of the Labour party, Tom Watson attributes his dramatic 94lb weight loss (including putting butter in his coffee every morning) in less than a year to following this plan and more importantly says he feels healthier and happier than ever

At the other extreme the low carbohydrate consumption association with premature death also found in this latest Lancet study is likely a reflection of this particular group not consuming enough vegetables which are abundant in antioxidants and polyphenols, an organic chemical, that exert a beneficial effect in reducing inflammation within the body.

Diet and lifestyle-related diseases

As with heart disease, chronic inflammation is being increasingly accepted within the scientific community as a driver of many chronic diseases including type 2 diabetes, dementia and even cancer. But educating the public on an individual level needs to be translated into helping the population as a whole if we are to reverse the twin epidemics of obesity and type 2 diabetes and solve the NHS crisis with increasing demand now predominantly being driven by diet and lifestyle-related diseases.

This will require a massive reduction in our consumption of ultra-processed food (a simple rule of thumb is any packaged food that contains more than five ingredients) which now makes up a staggering half of the British diet. It’s instructive to note this is predominantly made up of cheap heavily processed sugar and carbohydrates, not fat. The likes of cakes, chocolates, biscuits, crisps and sugary drinks have saturated the food environment making them almost unavoidable. Even our hospitals have become a branding opportunity for the junk food industry.

‘For years we’ve been misled by low-fat foods marketed as healthy which have been laden with shocking levels of sugar’

As with cigarettes making such nutritionally deficient, energy dense food items less available, less affordable (through taxation) and less acceptable to the public will have the biggest impact in curbing our ever-increasing waistlines. This will require political intervention and regulation to protect citizens from the excesses and manipulations of industry. For years we’ve been misled by low-fat foods marketed as healthy which have been laden with shocking levels of sugar.

Perhaps Tom Watson is the man to lead the charge, being bold enough to admit on Radio 4 Westminster hour that after suffering with obesity for 20 years from following conventional advice he decided to ignore and now challenge Public Health England’s Guidelines that suggest we should base our diet on starchy carbohydrates. But until further effective government action is taken to build on the welcome implementation of the sugary drinks tax, and dietary guidelines are updated the message should be loud and clear, eat real food.

Dr Aseem Malhotra is an NHS Consultant Cardiologist. All personal royalties from the sale of his book, The Pioppi Diet, is being donated to charity.