The science behind RFK Jr’s new diet advice – and it’s not all wild

Donald Trump’s Health Secretary, Robert F Kennedy Jr, is continuing to bulldoze through mainstream medical opinion after rewriting the US’s healthy eating advice.

Some of the recommendations – such as frying food in beef dripping and banishing low-fat dairy products – have drawn outrage from dietitians. But others are being hailed as welcome change.

Things become clearer once the advice is viewed through the lens of two overarching dietary principles that RFK has long championed.

The first, and most controversial, is the idea that people should be eating more meat and less carbohydrate, which includes both sugary treats and starchy foods like pasta, rice and bread. Extreme low-carbing is also called the Atkins or ketogenic diet.

The second principle, which is less provocative, is about cooking meals from scratch rather than eating highly processed food, also called ultra-processed food or UPF.

This idea, while not yet a part of official NHS advice, has become increasingly popular among experts and the public alike in the past few years.

So, how do these principles shape the specific food recommendations in RFK’s guidance – and what do other experts think?

Red meat is back on the menu

NHS healthy eating guidelines say we should limit red meat mainly as it is high in fat, especially saturated fat, said to be bad for the heart. RFK’s guidelines advise people to eat “a variety of protein foods from animal sources, including eggs, poultry, seafood, and red meat”, as well as plant-based proteins.

To illustrate the U-turn, a hearty beef steak, marbled with fat, sits on top of the US’s new “food pyramid” illustration – and is joined by what looks like a pack of beef mince for good measure.

This is one of the most controversial aspects of the guidelines, and contradicts healthy eating advice in most other countries. “We know that diets high in saturated fat are associated with high cholesterol and therefore higher risk of heart disease and stroke,” said Bridget Benelam, a scientist at the British Nutrition Foundation.

But RFK’s panel, who drew up the new advice, are not the only ones to think red meat has been unfairly maligned. In fact, randomised trials of cutting out red meat have given a mixture of results, with some finding health benefits and others not.

Fry in beef dripping

NHS and the old US guidance say we should use vegetable oils for cooking as these have little saturated fat.

The new pyramid says we should have “healthy fats”, comprising olive oil, butter or “beef tallow”, the fat released when beef is roasted, which Brits call beef dripping. The latter two are high in saturated fat.

The guidelines do say that people should try to make sure that saturated fat provides no more than 10 per cent of their calories, about the same as UK advice – but that would be unlikely if people are loading up on red meat, butter and tallow, said Benelam.

“Nobody has any way of knowing what percentage of calories they’re getting from fat,” she said. “If you simply follow the guidance on what foods to choose, then the likelihood is you’re getting quite a number of saturated fat foods in your diet.”

Full-fat dairy

Another change is that people are advised to use full-fat dairy products like milk, yogurt and cheese. Lower-fat dairy products are recommended by the NHS because the fat in milk is mostly saturated.

But the change on dairy is less controversial, as several studies find that people who have more full-fat dairy have lower risk of heart disease.

It seems that either there is something about dairy saturated fat that makes it uniquely beneficial rather than harmful – or perhaps milk has other components that outweigh any harms, for instance calcium or vitamin D.

“When it comes to eating full fat dairy products, it doesn’t seem to have the same impact that you would predict from its saturated fat content. And there’s lots of debate about why that might be,” said Benelam.

Doubling the protein

In line with the advice to load up on meat, Americans are now urged to eat more protein. The guidelines say they should have 1.2-1.6g of protein per kg of body weight per day, twice the amount previously advised.

The NHS also says we need to eat the lower amount of 0.75g/kg/day, which is about 45g in total per day for a typical women and 55g for a man. For context, half a chicken breast has about 30g of protein.

For most people, having more than recommended protein levels shouldn’t be directly harmful, said Kirsten Jackson, a spokesperson for the British Dietetic Association.

“But if we’re consuming more protein than we need, that typically means that on that plate there are less vegetables, less whole grains, all those foods that we know are really good.”

Carbs to the bottom

Leaving less space for starchy food is precisely the point, though. Reflecting the low-carb ethos, starchy food has been pushed to the bottom of the pyramid.

And while previous US guidelines recommended limiting sugar, the new version takes a harder line, saying “no amount of added sugars or [artificial] sweeteners is considered part of a healthy or nutritious diet”.

Dr David Unwin, a GP and diabetes expert in Southport, said people with type 2 diabetes would benefit from having fewer starchy carbs as well as sugar. “I’m so pleased to see refined carbs down at the bottom,” he said. “I believe this could really improve the health of America.”

But other dietitians are unhappy that starchy food is being pushed out. “Whole grains are very important in terms of giving us fibre that we know is good for our metabolic health and [reducing] chronic disease health,” said Danielle Battram, head of Brescia School of Food and Nutritional Sciences at Western University in Canada.

Cooking from scratch

Most dietary guidelines have long focussed on getting people to cut out fat, salt and sugar, without caring if meals are home-made or bought as ready meals or other forms of prepared food, like pasta sauces and snacks. NHS guidance is neutral on whether people need to cook from scratch, for instance.

But few can now be unaware of the crusade against highly processed food, spearheaded in the UK by TV doctor Chris van Tulleken, and gaining popularity in the US too.

RFK’s new food guidelines have for the first time in the US explicitly advised people to eat “real food” instead of highly processed versions. This is one area where he is in line with other dietitians. “That’s a huge win,” said Jackson.

Van Tulleken said: “There are welcome elements in these guidelines – for example they emphasise minimally processed foods and reducing added sugars. However the report also emphasises lots of food high in saturated fat so this may be confusing for people.”

Benelam said: “People will think nutritionists can’t make up their mind. What’s good one day is bad the next, and so you may as well eat what you like – which isn’t a helpful outcome at all.”