Drn Jacquie Lavin, Slimming World

Dr Jacquie Lavin, Head of Nutrition and Research at Slimming World, discusses how sustainable weight-loss plans should be healthy, balanced and flexible.

We’re bombarded with stories in the news about diets, and most recently, it seems to be carbohydrates that are getting the attention.  

One minute we read carbohydrate-rich, low-fat diets are good for us, and the next we see reports suggesting high-carbohydrate diets are a risk to health and cause weight gain. This understandably leads to massive confusion.
A recent survey by Slimming World and YouGov found that more than 70% of the general population surveyed have tried to lose weight, with more than a third of them following a low-carbohydrate diet. 

However, the Scientific Advisory Committee on Nutrition (SACN) review of all available evidence of the relationship between dietary carbohydrate, fibre and health in 2015 recommended that carbohydrates should provide around half our energy needs. They concluded the current evidence doesn’t support the suggestion that diets higher in carbohydrate cause weight gain.

Despite this many people still believe that diets restricting carbohydrates are the way forward for healthy weight loss. Contrary to the scientific advice, two thirds (66%) of the 2,103 survey respondents had heard that low-carbohydrate diets are better for weight loss, and just over one third (35%) had heard that it was impossible to lose weight without cutting carbohydrates. 

There is no disputing that low-carbohydrate diets may help people lose some weight, but they can be hard to sustain. Respondents to our survey reported feeling hungry, bored and restricted in what they could eat when undertaking low-carbohydrate plans and cutting out starchy carbohydrates like potatoes, pasta, rice and bread – and we know from previous research that these are key reasons why people give up on weight-loss attempts. 

Satisfying the appetite is key for long-term weight control. Research shows protein and carbohydrate-rich foods are more satiating than fats, they fill you up sooner and for longer for fewer calories. Protein is the most satiating, followed by carbohydrate and then fat. Fibre-rich carbohydrates are particularly satiating. Fibre adds bulk to foods making them take longer to digest and absorb and lowers the energy density, helping fill you up for fewer calories.

Whilst being sustainable for the long term, a diet to aid weight loss also needs to be healthy and balanced. It should give people the freedom and flexibility to enjoy a healthy balance of protein, carbohydrates and fat – plus lots of fruit and vegetables.

It’s never a good idea to restrict any food group as this can make it difficult to achieve a balanced diet. A very low-carbohydrate diet would inevitably limit intake of cereals, grains, starchy vegetables (potentially also non-starchy vegetables and fruit), beans and pulses, and thereby limit intake of many beneficial vitamins, minerals and particularly fibre – all of which contribute to good health. 

Sugar however, whilst a form of carbohydrate, has little nutritional benefit on its own, and unlike other more complex carbohydrates, consuming a lot of sugar is linked to weight gain and poorer health. 

Obesity has an impact on our own personal health and puts a massive strain on our National Health Service, which has to deal with numerous obesity-related conditions. People need help and advice to lose weight and keep it off.

Suggesting overweight people need to follow low-carbohydrate diets, which we know are hard to sustain and potentially cut out a group of foods that are important for a healthy balanced diet, is irresponsible. It sets people up to fail in the long-term – it’s likely to leave them struggling with feelings of guilt and low self-esteem, as well as potentially regaining the weight they lost. 

With the obesity crisis increasing it is vitally important we stop demonising carbohydrates as a food group and provide people who’d like to lose weight with accurate information.

Read Slimming World’s full report Carbfusion: How confusion about the role of carbohydrates in our diet is damaging the nation's health.