Minimally processed - maximum weight loss

Why processing matters

A new UK study, published in Nature Medicine, shows that people who eat minimally processed meals - mostly home-cooked dishes made from natural ingredients - lose around twice as much weight as those following a diet based on ultra-processed foods. And this holds true even when the processed foods are considered “healthy” and meet all official nutrient guidelines. The difference in processing level alone made the impact.

How the study worked

Overweight participants followed either a home-cooked or ultra-processed diet for eight weeks, with nutrient and calorie content matched according to the UK’s Eatwell Guide. Afterwards, the groups switched diets. Everyone could eat as much or as little as they wanted - up to 4,000 kcal per day.
Meals on the minimally processed diet included things like overnight oats or homemade pasta, while the ultra-processed diet featured foods such as breakfast bars or frozen ready meals. Minimally processed foods are typically made from natural ingredients like fruit, vegetables, and animal products. In contrast, ultra-processed foods often contain numerous additives and are high in sugar, salt, fat, and calories, but low in fiber.

Impact on calorie intake and body metrics

On the ultra-processed diet, participants consumed on average 120 fewer calories per day than they did with their regular eating habits - on the minimally processed diet, the reduction was around 290 kcal per day. This difference led to significantly greater weight loss. Participants also showed improvements in body fat and triglyceride levels, while LDL cholesterol dropped equally or even more under both diets.

The key takeaway

For lasting weight loss - without strict diets or calorie counting - it's better to focus on unprocessed, real food. It helps you feel full for longer, curbs appetite naturally, and reduces overall calorie intake. Mindful eating without restriction - but with far more effect.