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Healthy eating in practice: what the evidence shows and what actually works

Most nutrition advice is contradictory. Here is what the research consistently supports.

What the evidence consistently shows

The research consistently supports: eating plenty of vegetables and fruit (at least 5 portions per day, ideally more), minimising ultra-processed foods (associated with worse health outcomes across studies), adequate protein (particularly important for older adults and active people), eating mostly whole foods, and maintaining a broadly balanced energy intake. The Mediterranean dietary pattern — most studied of all — consistently shows positive outcomes for cardiovascular health, longevity and cognitive function.

What the evidence does NOT clearly support

Many popular dietary strategies — strict keto, juice cleanses, detox diets, specific superfoods — have weak or mixed evidence bases. The 'best diet' research consistently shows that the best diet is one that is sustainable for the individual, provides adequate nutrition, and doesn't require constant vigilance. Compliance beats perfection: a moderately healthy diet maintained consistently produces better outcomes than a perfect diet followed intermittently.

Practical daily habits that work

Pre-planning meals (our free weekly meal planner and food diary) reduces impulsive food decisions. Vegetables as the foundation of every meal, with protein and carbohydrate completing the plate. Cooking at home rather than eating out, with batch cooking (our free meal prep planner) reducing daily decision fatigue. Not keeping ultra-processed snacks in the house.

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Frequently asked questions

Is there one food everyone should eat more of?
Vegetables — specifically a variety of colours. The evidence for plant diversity in the diet is among the strongest in nutrition science. Each additional vegetable colour or variety provides different phytonutrients. 'Eat the rainbow' is genuinely evidence-backed advice, rare in the nutrition world where most guidance is contested.
Are carbohydrates bad for you?
No — the quality and context of carbohydrates matters more than the quantity. Whole grains, legumes, vegetables and fruit are carbohydrates with excellent evidence bases. Refined carbohydrates and added sugars (particularly in ultra-processed foods and drinks) have negative associations in the research. The carbohydrate is not the problem; the processing is.