Healthy eating · Two principles

Processed vs Whole Foods and Eating More Plants: The Bottom Line

Behind every fad diet, two questions keep coming back: how processed, and how much from plants?

Principle 1: processed vs whole foods

Processing covers a lot: cooking, freezing, pasteurising milk and canning all count. SACN notes that processing can make foods edible and safe. The concern is with foods that are high in energy, saturated fat, salt and free sugars and low in fibre, many of which are heavily processed.

Illustrative examples only. Check the label: processing level and nutrient content don’t always line up.
Usually a useful everyday choice	Worth having less often
Frozen or canned vegetables and fruit (in water or juice)	Sugary soft drinks
Canned beans, lentils and chickpeas	Processed meats such as bacon, sausages and salami
Wholemeal bread, oats and wholewheat pasta	Cakes, biscuits, pastries and sweets
Plain yoghurt and milk	Crisps and salty snacks

What UK experts say about ultra-processed food

The UK’s Scientific Advisory Committee on Nutrition (SACN) reviewed the evidence in 2023 and again in April 2025. Its conclusions (SACN):

Links between eating more (ultra-)processed food and poorer health are concerning.
The evidence is almost entirely observational, so it is unclear whether processing itself is the problem, or the fact that most of these foods are high in calories, saturated fat, salt and sugar.
On balance, most people are likely to benefit from eating fewer processed foods high in energy, saturated fat, salt and free sugars, and low in fibre, which matches existing advice, including minimising sugar-sweetened drinks and avoiding high intakes of red and processed meat.

SACN said it would keep the topic under review. In practice, the advice for shoppers is the same either way: use the label, and favour foods closer to how they started.

Principle 2: eat more plants

The Eatwell Guide puts fruit and vegetables and higher-fibre starchy foods at the centre of the plate, and suggests beans and pulses as part of the protein group. For meat, the NHS says that if you eat more than 90g (cooked weight) of red or processed meat a day, you should cut down to 70g, because eating a lot probably increases bowel cancer risk (NHS).

You don’t have to be vegetarian or vegan. The NHS says a well-planned vegan diet can provide the nutrients you need, but needs attention to vitamin B12, iodine, calcium, iron and selenium, sometimes through fortified foods or supplements (NHS). The WHO also recommends a wide variety of foods including fruit, vegetables, whole grains, legumes, nuts and seeds (WHO).

Everyday examples

Swap a sugary drink for water, milk or unsweetened tea or coffee.
Add a can of beans or lentils to a chilli, curry or soup and use less meat.
Keep frozen vegetables in for quick meals.
Choose wholegrain versions of bread, rice and pasta. See whole vs refined grains.
Compare labels: how to read nutrition labels.

Balance, not perfection

An occasional takeaway or packet snack doesn’t undo an otherwise balanced diet. What matters is the pattern over weeks and months.

Common questions

Are all processed foods bad?

No. Frozen vegetables, canned beans, wholemeal bread and pasteurised milk are processed and can be part of a healthy diet. The concern is with foods high in calories, saturated fat, salt and sugar and low in fibre.

Are ultra-processed foods proven to be harmful?

Not proven. SACN found the links concerning but the evidence mostly observational, so it can’t yet say whether processing itself causes harm.

Do I need a plant-based diet to be healthy?

No, but most healthy eating guidance is plant-forward. You can include meat, fish, eggs and dairy while making plants the bulk of your meals.

How much red meat is OK?

The NHS suggests that people eating more than 90g of red or processed meat a day cut down to 70g.

Keep learning

Put it into practice: 8 changes, one a week