nutritionist’s verdict on the new US diet rules

 When Robert F Kennedy Jr shares health advice, doctors cringe and hold their breath. Some of the previous nuggets of information he has spouted – from repeating debunked anti-vax misinformation to claiming that fluoridated water is harmful – have no scientific basis. However, his latest move to overhaul national nutrition advice has garnered some support from experts.

Health problems in the US largely mirror Britain’s. Seven in 10 adults are overweight (compared to 64 per cent in England); 66 per cent of Americans’ diet is ultra-processed (the figure is 57 per cent in the UK). The US spends 90 per cent of healthcare funding on treating chronic diseases linked to weight and lifestyle choices. In the UK, the total cost in 2025 linked to health complications due to being overweight or obese has been put at £126bn.

However, the US picture is worse in some areas. Their breakfast cereals are more sugary than Britain’s, fast food is more calorific and, famously, chlorinated chicken is the standard.

In his bid to clean up America’s diet, RFK Jr has inverted the food pyramid to prioritise protein, take a stronger stance against ultra-processed food and reframe the narrative on fat, which has been routinely demonised.

It’s a move that’s been backed by some experts. Our columnist and award-winning scientist Tim Spector has called it a “genuinely welcome shift”; longevity guru Dr Mark Hyman argues it’s a “course correction”; and biohacker Bryan Johnson labelled it a “significant upgrade”.

However, not all are convinced. “Kennedy seems to have put populist opinion over evidence-based science,” says Thomas Sanders, emeritus professor of nutrition and dietetics at King’s College London, who has published more than 250 scientific papers on how diet impacts our health. Some of the advice – prioritising eating plenty of fruit and vegetables and more wholegrains – is sensible, but other areas are “nonsense”, he says.

So, what are the changes, and is there anything Britain should learn from them?

Eat more protein

What it is

“We’re ending the war on protein,” the new US health recommendations declare. In the pyramid imagery accompanying the changes, chicken and steak are given the same prominence as broccoli and carrots. Americans are told to prioritise animal proteins such as meat, seafood, eggs and full-fat yogurt and milk. Plant-based protein sources, such as legumes, nuts and seeds, are mentioned but given less prominence.

Adults are advised to eat 1.2g to 1.8g of protein per kilogram of body weight per day, which is around 110g to 164g for American men (equivalent to five chicken breasts); or 94g to 140g for women (equivalent to four chicken breasts).

How it’s different from Britain

Protein is billed much less prominently in the UK, with vegetables, fruit and carbohydrates prioritised instead. Health chiefs advise adults to consume 0.8g of protein per kg of body weight, which is around 45g to 55g daily (equivalent to one-and-a-half chicken breasts).

However, Brits have much more than this. Adults aged 19 to 64 consume 76g per day, while over-65s have 67g per day. Both figures exceed the daily recommendations.

Nutritionist verdict

“I disagree with protein recommendation,” Prof Sanders says. “Americans eat more than enough protein already. High intakes of protein particularly from red meat are associated with an increased risk of cancer of the colon, breast and prostate,” as well as cardiovascular disease, he notes.

“Protein recommendations are made to maintain lean body mass, and people who are obese or overweight – which includes most Americans – don’t need extra protein. Eating more protein will not mean muscle mass is retained or built up, particularly if it is not accompanied by strength training.”

Have three vegetables and two pieces of fruit daily

What it is

“Eat a wide variety of whole, colourful, nutrient-dense vegetables and fruits in the original form, prioritising freshness and minimal processing,” the guidelines state. It recommends eating three servings of vegetables and two of fruit per day. “Frozen, dried or canned vegetables or fruits with no or very limited added sugars can also be good options.”

How it’s different to Britain

We’re told to eat at least five 80g portions of fruit and vegetables per day. A 150ml glass of 100 per cent fruit juice and a 30g serving of dried fruit can also count towards the target. However, only around a fifth of adults achieve it.