Men in Tanzania switched from an African diet to a Western one — here’s what happened to their bodies

We’ve all heard how Mediterranean, Japanese and other traditional diets can work wonders for our health, but what if the tables were turned? 

In a bold new experiment, researchers asked Tanzanian men to swap their plant-based, fiber-rich diets for a Western-style regimen filled with calorie-dense, processed foods.

It took just two weeks for the shocking effects to show up in their bodies — and the consequences lingered after they returned to their normal ways of life. 

For the study, researchers from Radboud University and KCMC University in Tanzania joined forces to investigate the effects of a diet swap on 77 healthy young men from rural and urban Tanzania. 

Participants who regularly ate traditional Kilimanjaro diets were instructed to switch to a Western diet, which included foods like beef sausage, fried chicken, pizza, potato chips, white rice, macaroni, eggs and very few fruits or vegetables.

The results were alarming: after just two weeks, the men gained an average of 5.7 pounds.

Their blood also showed an increase in inflammatory proteins, as well as metabolic changes linked to chronic conditions like heart disease and type 2 diabetes. 

Worse still, their immune cells became less effective at fighting off dangerous pathogens, making them more vulnerable to infections.

Even after the participants returned to their usual diets, some of the negative effects lingered for up to four weeks, highlighting how short-term dietary changes can have lasting consequences, the study authors noted. 

The study didn’t end there. Researchers also tested what would happen if participants who typically followed a Western diet switched to a traditional African one. 

These men followed a traditional Kilimanjaro diet for two weeks, which was packed with vegetables, fruits, legumes, brown rice, whole grains, roots and tubers, as well as fermented foods. Meat consumption, typically limited to once or twice a week, primarily involved local free-range chicken and fish. 

Researchers observed the opposite effect in those who switched to the traditional African diet. These men experienced a reduction in inflammatory proteins and positive metabolic changes in their blood.

The findings come as Western eating habits are increasingly adopted across Africa, coinciding with a surge in chronic conditions driven by inflammation, such as heart disease, type 2 diabetes and cancer.

“The African diet includes plenty of vegetables, fruits, beans, whole grains, and fermented foods,” said Dr. Quirijn de Mast, an internist and infectious disease specialist at Radboud University. “Our study highlights the benefits of these traditional food products for inflammation and metabolic processes in the body.”

“At the same time, we show how harmful an unhealthy Western diet can be,” he continued. 

Curious about trying a traditional African diet? Start here.

Radboud University shared a traditional Tanzanian recipe for Ugali (corn porridge) and Mchicha (curry with spinach and peanuts).

Ingredients (serves four):

• 500 grams maize flour
• 900 grams chopped spinach
• 2 tbsp peanut butter
• 2 chopped tomatoes
• 1 chopped red onion
• 2-3 tbsp curry powder
• 1 cup coconut milk
• Pinch of salt and a crack of freshly ground black pepper

Step 1: Make the Ugali

1. Boil 1 liter of water.
2. Add the cornmeal while stirring.
3. Boil for 10-15 minutes, stirring frequently, until it becomes firm. Add more water if necessary.

Step 2: Make the Mchicha

1. Mix peanut butter and coconut milk.
2. Heat a skillet and fry the onion, tomatoes, salt, and curry powder until the onions are soft.
3. Add spinach and heat briefly.
4. Add the coconut mixture and mix well.
5. Cook until heated through and finish with a crack of pepper.
6. Cook until heated through and finish with pepper.