Eating for better health can quickly become complicated, with competing advice about protein, supplements, fasting, and 'longevity foods'. But Dr Ezekiel Emanuel, an oncologist and public health professor, says people do not need to overhaul their entire diet to make meaningful improvements.

Speaking to Business Insider following the launch of his book Eat Your Ice Cream, Emanuel outlined four simple changes he considers the biggest 'bang for your buck' when it comes to reducing chronic disease risk.

His approach is less about perfection and more about making sustainable changes that can become part of everyday life.

1. Eat More Fermented Foods

Emanuel's first recommendation is to add fermented foods such as kimchi, sauerkraut, miso, and kefir to your diet.

These foods can contain live microorganisms and other compounds that may support the gut microbiome. Research has linked greater microbiome diversity with aspects of better metabolic and immune health, although the relationship between individual foods and long-term disease outcomes is still being studied.

Emanuel described fermented foods as an easy dietary change with potentially significant benefits. The practical takeaway is simple: choose fermented foods you actually enjoy rather than forcing yourself to eat something you dislike.

2. Cut Back on Sugary Drinks

The second rule is to reduce sugary drinks.

Emanuel recommends cutting consumption to no more than one or two servings a week, arguing that regular intake can contribute to problems including type 2 diabetes, cardiovascular disease, and liver disease.

The American Cancer Society also recommends limiting sugar-sweetened beverages as part of a healthy eating pattern.

Replacing sugary drinks with water or unsweetened alternatives can therefore be a relatively straightforward way to reduce added sugar without changing entire meals.

3. Eat Fewer Ultra-Processed Snacks

Emanuel also recommends cutting down on packaged snack foods such as crisps, biscuits, and packaged cakes.

The distinction is important because the term 'ultra-processed food' covers a broad range of products, including some foods that can still have nutritional value. Emanuel instead focuses on what he calls 'junk food', particularly products high in salt, sugar and fat with relatively little nutritional value.

The American Cancer Society recommends limiting highly processed foods and refined grain products, alongside sugar-sweetened drinks and processed meats.

Rather than banning snacks entirely, replacing some packaged foods with whole fruit, nuts or other minimally processed options can make the change more sustainable.

4. Make Fibre a Priority

The fourth recommendation is to eat more fibre.

Emanuel says adults should aim for around 30 to 35 g of fibre a day, noting that many Americans consume considerably less. Good sources include fruit, vegetables, beans, nuts and whole grains.

Fibre supports digestive health and can help regulate how quickly glucose enters the bloodstream. It also provides fuel for beneficial gut bacteria.

The American Cancer Society similarly recommends a diet rich in vegetables, fruits, legumes and whole grains, all of which can contribute fibre.

You Do Not Have to Eat Perfectly

Perhaps the most notable part of Emanuel's advice is that he recommends not obsessing over every calorie, nutrient or health metric.

He argues that healthy eating should fit around people's lives rather than become an all-consuming project. An occasional dessert or indulgence does not undo an otherwise healthy dietary pattern.

That philosophy broadly aligns with guidance from the American Cancer Society, which emphasises an overall healthy eating pattern rather than eliminating every individual food. Its recommendations prioritise vegetables, fruits, whole grains and legumes while limiting sugary drinks, highly processed foods and processed meats.

Ultimately, Emanuel's four rules are less about following a rigid 'longevity diet' and more about making a handful of practical swaps: add more fibre and fermented foods, while cutting back on sugary drinks and heavily processed snack foods.

For people overwhelmed by constantly changing nutrition trends, that simplicity may be the most useful advice of all.

Frequently Asked Questions

  • What are the benefits of eating fermented foods?
    Fermented foods can support the gut microbiome, which is linked to better metabolic and immune health.
  • Why should sugary drinks be limited?
    Regular consumption of sugary drinks can contribute to health issues such as type 2 diabetes, cardiovascular disease, and liver disease.
  • What are some healthier alternatives to ultra-processed snacks?
    Healthier alternatives include fruits, nuts, and other minimally processed options.
  • How much fibre should adults aim to consume daily?
    Adults should aim for around 30 to 35g of fibre a day.
Read more