Will a Minimally Processed Diet Help with Weight Control?

Ultra-processed food has a reputation for contributing to chronic disease. A minimally processed diet, on the other hand, is associated with good health. However, it is often perceived as too pricy or time-consuming. Too often, ultra-processed food is cheap and readily available, even in food deserts. It is also designed to be appealing.

Comparing a Minimally Processed Diet to an Ultra-processed One:

Researchers wonder whether it is the foods themselves or something else about people who choose an ultra-processed diet that is responsible for the apparent problems. To find out, scientists in England conducted a comparative experiment (Nature Medicine, August 4, 2025).

They assigned 55 overweight people to follow a minimally processed diet and an ultra-processed diet for 8 weeks each. The diets adhered to the UK Eatwell nutrition guidelines. Even the ultra-processed items fit the guidelines, including presumably healthful foods such as breakfast cereals, protein bars and chicken sandwiches low in fat and salt. For the minimally processed diet, participants got foods like overnight oats, chicken salad, and homemade spaghetti bolognese. The order in which the diets were provided was determined randomly, so some volunteers spent the first two months eating plain foods and others during the same time were eating processed foods. After a 4-week washout period, they switched to the other test diet. The main outcome for the study was percent change in weight for each participant.

Were People Able to Lose Weight?

One classic difficulty of weight loss studies is that participants may drop out. That also happened in this study, even though the investigators provided the food. Nonetheless, 45 people completed the trial. Both diets resulted in weight loss. However, most people lost more weight on minimally processed food. On average, weight loss doubled on such diets. People also lost twice as much body fat. However, the ultra-processed diet lowered undesirable LDL cholesterol more. Volunteers reported fewer food cravings while on the minimally processed diet. The researchers say that their study shows following nutrition guidelines really can be helpful, especially if you focus on minimally processed foods. They suggest that people might need more help understanding and implementing these guidelines in their daily lives.

Learn More:

We have discussed the dangers of ultra-processed foods with several health experts. To get a broader sense of where the research is heading, you may want to listen to Show 1359: Is the Food on Your Plate Real or Fake?  There is also Show 1202: How Can We Fix Our Broken Food System? Another interview on the link between diet and weight is Show 1332: What Everyone Gets Wrong About Weight Loss.