Should you really eat fat to stay slim? The new food rules explained

For consumers, the furore was yet another recipe for confusion when it comes to healthy eating. 

What is clear is that the UK has a serious health problem. In England, 25 per cent of adults are obese and the number of people with Type 2 diabetes has doubled in the past 20 years to almost 3.5 million. PHE argues that we have these problems because, as a nation, we don’t observe official health guidelines, consuming too much sugar and too much saturated fat. The authors of the NOF report disagree and say the guidelines are wrong.

Dr David Unwin, a GP in Merseyside who contributed to the report, believes we just need to focus on a few rules if we want to eat well. “There’s a lot that health experts agree on,” he says. “We need to concentrate on some simple messages.”

Here, we outline everything you should – and shouldn’t – be eating.

Eggs

Un oeuf is un oeuf. It is now safe to eat eggs. Previous links to high cholesterol and heart disease have been revised and daily limits scrapped.

Starchy foods

Official advice to base meals around bread, pasta and rice are being challenged by some experts who say these foods cause blood sugar to rise, increasing the risk of diabetes. Low-carb diets are recognised as good for weight loss and reducing the risk of Type 2 diabetes.

Low fat

Once the diet du jour, research now shows that low-fat diets are ineffective, and that some fats benefit our health. Most experts worry that low-fat products such as yogurt often contain lots of added sugar.

Margarine and spreads

Still recommended by public health officials as a way to limit our intake of saturated fats, some experts advocate butter as a more natural option.

Nuts

Once had a dubious reputation for being high in fat and calories, but are now regarded as a key part of a healthy diet.

Red meat

Health guidelines suggest eating no more than 70g per day. The World Health Organisation has classified red meat as a “probable” trigger for cancer, but some experts have questioned the research behind this.

Sugar and starchy carbs

Almost everyone agrees that sugar damages our health. Official guidelines say we should limit our daily intake of added sugar to 25g or six teaspoons a day. This includes honey, syrups and fruit juice.

But opinion is divided over starchy carbohydrates. The UK’s recently revised Eatwell Guide recommends we base our meals around carbs such as wholegrain bread, rice and pasta – wholegrain where possible. But the NOF report suggests this advice is making our health worse.

Dr Unwin has successfully treated patients for obesity and Type 2 diabetes by encouraging them to switch to lower carbohydrate diets.

“I used to tell patients to give up eggs, cheese and butter in line with the official guidelines, but it didn’t seem to work,” he says. “When I saw how much sugar comes out of starchy carbs I was shocked. I realised why they struggled to lose weight.”

Anna Daniels, a dietitian, agrees that low-carb diets can help weight loss, but adds that wholegrains can help prevent cancers and are full of fibre. “Not all carbs are equal,” she says.

Should I eat fat?

Past advice promoted low-fat diets, but newer research shows that some fats are essential. Scientists agree about the “good” fats.

Mono-unsaturated fats, in olive oil, avocados and most nuts, help protect our hearts by maintaining levels of “good” HDL cholesterol, while reducing levels of “bad” LDL cholesterol.

There are two main types of polyunsaturated fats: omega 3 fatty acids (in oily fish) and omega 6 fatty acids (in vegetable oils).

There’s a consensus, too, that artificial transfats in processed foods such as biscuits and cakes are bad news. Transfats increase the risk of disease, even in small amounts.

But saturated fats in red meat and dairy are contested. The NOF report claims there is no solid evidence to support the official wisdom that saturated fat raises cholesterol levels and increases the risk of heart disease.

In fact, the report argues, saturated fats in full-fat dairy can protect your heart, and there should be no limit on the amount of fat we eat.

This runs against official guidelines recommending that no more than 30 per cent of our calories should come from fat, and that we should stick to low-fat dairy, and unsaturated oils and spreads.

PHE says this advice is based on the fact that, as a nation, we eat more saturated fat than we should; a limit of 20g a day is recommended for women and 30g for men. 

Anna Daniels, a dietitian, says the healthiness of saturated fat depends on the food.

“People who over-consume saturated fat may eat it in food such as pies and pastries, which are full of unhealthy refined carbs,” she says.

“A little butter might not be an issue. But if you have high cholesterol, then switching to a monounsaturated spread such as olive oil would be beneficial.”

Cholesterol

Cholesterol was long considered a dietary demon along with fat. Experts believed that cholesterol-rich eggs, for example, clogged our arteries and caused heart disease, so public health officials urged us to limit our intake to one a day.

As it turns out, there was no evidence to support the link between egg consumption and heart disease or stroke, so restrictions were lifted.

‘Real’ food

Amid all the claims and counterclaims in the latest skirmish over healthy eating, there is some common ground. 

Dr David Nunan, Departmental Lecturer in Evidence-Based Medicine at Oxford University, says there is little dispute that a Mediterranean-style diet is a good model. “This consists mainly of vegetables, fruit (but not fruit juice), unsalted nuts, olive oil, seafood (especially oily fish), lean meat, legumes, beans and pulses, and wholegrain carbohydrates,” he says.

But the toughest guideline for many people – and the most crucial – is to eat real food. “Limit your intake of highly processed foods,” says Dr Nunan. “If the packaging lists more than five to 10 ingredients, then it is probably highly processed.”

If only every message in the food debate were that simple.

Food to avoid

•  Highly processed foods with five to 10 ingredients (or more)
•  Fizzy drinks, flavoured milks, flavoured yogurt and yogurt drinks, cordial and syrups
•  Fruit juice and fruit juice concentrates (no more than 150ml per day)
•  Processed, baked and fried foods containing artificial transfats (hydrogenated fat) and refined sugars
•  Processed red meat
•  Snacks between meals 

Food to eat

•  Meals cooked from scratch with fresh, raw or whole ingredients
•  Vegetables – especially green, leafy ones
•  Good fats – olive oil, avocados, nuts and oily fish
•  Whole grains