Robert F Kennedy Jr has set his sights on changing how Americans eat and drink.

From the dyes in Fruit Loops cereal to seed oils in chicken nuggets, Kennedy – who is President-elect Trump’s choice to lead the Department of Health and Human Services (DHHS) – has long spoken out against ingredients that he says hurt Americans’ health.

“We are betraying our children by letting [food] industries poison them,” Kennedy said at a rally in November, after he had ended his independent presidential bid and backed Donald Trump.

But if Kennedy hopes to target junk food, he will first have to shake up the country’s food regulations – and run up against Big Food.

“What he’s suggesting is taking on the food industry,” said former New York University nutrition professor Marion Nestle. “Will Trump back him up on that? I’ll believe it when I see it.”

The former environmental attorney – who still must face confirmation by the Senate – is considered by many to be a controversial pick, given his history of making baseless health claims, including that vaccines can cause autism and that wifi technology causes cancer.

Yet some of his ideas around reforming the FDA have found support from health experts, lawmakers and concerned consumers alike – including some Democrats.

Kennedy “will help make America healthy again by shaking up HHS and FDA”, Colorado’s Democratic Governor Jared Polis wrote on social media this week, welcoming his nomination. After receiving public backlash for praising him, Polis qualified his endorsement, writing on social media that “science must remain THE cornerstone of our nation’s health policy”.

Leading up to the election, Kennedy – a former Democrat – offered several ideas for tackling chronic diseases under his slogan “Make America Healthy Again”.

He has frequently advocated for eliminating ultra-processed foods – products altered to include added fats, starches and sugars, like frozen pizzas, crisps and sugary breakfast cereals, that are linked to health problems like cancer, cardiovascular disease and diabetes.

He has taken aim primarily at school lunches, telling Fox News: “We have a generation of kids who are swimming around in a toxic soup right now.”

Part of Kennedy’s new mandate will include overseeing the US Food and Drug Administration (FDA), which has over 18,000 employees.

The agency is in charge of ensuring the safety of pharmaceuticals and the US food supply, but has come under fire in recent years from some lawmakers and consumer groups, who have accused it of a lack of transparency and action on food safety.

The 70-year-old has pledged to take a sledgehammer to the agency, and fire employees he says are part of a “corrupt system”.

“There are entire departments, like the nutrition department at the FDA … that have to go, that are not doing their job,” Kennedy told MSNBC this month.

He has also pushed for getting rid of food dyes, including Red No. 3, and other additives banned in other countries.

The former Democrat has also singled out more controversial health issues, including fluoride in drinking water, which he says should be banned altogether, and raw milk, which he believes has health benefits despite the increased risk of bacterial contamination.

He’s also come after seed oils, writing on social media that Americans are being “unknowingly poisoned” by products like canola and sunflower oil that are used in fast foods.

Several public health experts stand behind Kennedy’s goal to tackle ultra-processed food, which they say the US eats at much higher rates than many other countries.

“It is just thrilling to hear somebody argue for doing something about chronic disease,” Ms Nestle said.

Kennedy’s aim to get rid of certain food additives and dyes also could be beneficial, said Dr Peter Lurie, executive director for the Center for Science in the Public Interest, a non-profit group that advocates for food safety.

The former FDA official said several food dyes, including Red No. 3 – which is banned in California – should also be blocked by the US government because of concerns about carcinogens.

The FDA has pushed back on Kennedy’s claim that the US allows thousands of additives that are banned in the European Union. A spokesperson said it was necessary “to dig deeper and understand the context behind the numbers” when comparing regulations in the US and EU, which use different methodologies.

But public health experts and former officials said a number of Kennedy’s goals were not worthwhile – and in some cases, harmful.

For instance, drinking raw milk that has not been pasteurized – a process that helps kill bacteria – can make people sick or even kill them, research has found.

“There’s no evidence of any nutritional benefit of any magnitude that we know that comes from non-pasteurizing of milk,” said Dr Lurie.

Kennedy’s proposal to remove fluoride from drinking water also could be problematic, because fluoride, in the low levels found in water, has been proven to improve dental health, said Ms Garner.

Removing it from the water supply would also be out of his jurisdiction, because fluoride levels are controlled by states.

And his claim that seed oils are helping drive the obesity epidemic is not based in science, either, Dr Lurie said.

“We see no evidence for that. In fact, they seem like important products to the extent that they substitute for saturated fats” such as butter, he said.

Food reforms, while long part of the public health conversation, could also simply be unrealistic both politically and bureaucratically, some experts said.

“It’s a good deal more complicated than he lets on,” said Dr Lurie. “These are real challenges, and you will encounter industry opposition at every turn.”

For one, the FDA does not have authority over the catch-all of “ultra-processed foods”, several former officials told the BBC.

Instead, they said, the process is more complicated. Both the US Department of Agriculture and the FDA regulate the food industry. The FDA does not make the rules – it carries out policies passed by Congress and works to limit unhealthy foods by enforcing limits and labelling on certain nutrients, like sodium and saturated fat.

Kennedy’s comments “make for great political rhetoric”, Ms Garner said. “In my view, I don’t see how that could be feasible without drastic changes in other policy and infrastructure.”

He will also face industry backlash for proposals to ban pesticides and genetically modified organisms commonly used by American farmers, former FDA officials said.

“The businesses will complain,” said Rosalie Lijinsky, a former FDA official of 33 years.

The industry is used to limited oversight from both Democrats and Republicans – including under Trump’s first term – while many of Kennedy’s goals would involve even more rulemaking.

Several food industry groups met with lawmakers before Kennedy’s appointment this month to lobby against him, Politico reported last month.

Republican Senator Chuck Grassley, of Iowa, said this week that he planned to meet Kennedy before his confirmation hearing and “spend a lot of time educating him about agriculture”.

Kennedy’s position also puts him at odds with President-elect Trump, a longtime lover of fast food who worked to roll back stricter health requirements for school lunches during his first term.

“You get some ideas that make a certain amount of sense, but they are exactly the kind to which this administration is hostile,” Dr Lurie said.

In a statement to the BBC, the Food Industry Association, which represents food retailers, producers and manufacturers, like General Mills, said it looked forward to working with Trump’s team to “ensure food and drug policy continues to be grounded in science, to reduce regulatory complexity”.

The industry complaints about Kennedy’s agenda do not come as a surprise, said Jeff Hutt, a spokesperson for the Make America Healthy Again political action committee, which is urging Republican lawmakers to confirm Kennedy.

The goal of the health movement, Mr Hutt said, is “prioritising the wellness of America over corporate profits”.

“Even if the idea of banning ultra-processed food is not possible politically, it’s a conversation that we need to have,” he said.

Kennedy still could work within existing US regulatory frameworks to improve America’s food systems, former officials said.

Ms Nestle said Kennedy could take on ultra-processed foods by altering the US Dietary Guidelines, which set nutritional standards for the industry and federal government programmes, including school lunches and military meals.

“They have an enormous impact on the food industry,” Ms Nestle said. “That would make a big difference.”

The guidelines are updated every five years by the US Department of Agriculture and DHHS, which has previously said there is not enough evidence against ultra-processed foods.

Still, officials and nutrition experts raised concerns about the means by which Kennedy has proposed to enact his agenda, including firing the FDA’s nutritionists.

The move would have large ramifications for food safety, said Ms Lijinsky. “If you lose your top experts, you’re going to have problems,” she said.

Ultimately, Ms Garner said it is difficult to disentangle some of Kennedy’s more reasonable food-improvement goals with the false health claims he has spread.

“There’s an opportunity here,” Ms Garner said.

“But I think there’s rightful concern based on other issues and how his approach to those issues might play in here.”