Group of men switched from plant-based diet to Western foods and saw huge impact it had on their bodies after two weeks

A new experiment has examined what happened when men from Tanzania switched their diets from food common in Africa to a more Western style.

At some point in time, we've all debated switching up our diets to feel a bit healthier, whether that be just trimming down carbs or seeing what a vegan diet holds for us.

While vegan vs. meat-eating has been scientifically explored before, what about eating habits from different countries?

Well, that's what researchers wanted to find out when they asked a group of 77 East African men to ditch their more traditional Tanzanian diet for a very specific kind of 'western diet'.

The 2025 study, entitled 'Immune and metabolic effects of African heritage diets versus Western diets in men: a randomized controlled trial' saw researchers from Radboud University and KCMC University join forces to see what impact a Western diet, containing largely processed foods, would have on the men's health after two weeks.

The 'western diet' wasn't the most healthy of food consumed in the West (Getty Stock Image)

The ‘Western diet’ included foods like beef sausage, fried chicken, pizza, potato chips, white rice, macaroni, eggs with limited fruits or vegetables - so hardly the cleanest food by anyone’s measurements.

As you can imagine, this diet didn’t exactly do wonders for their body.

According to the study, the men gained an average of 5.7 pounds and their blood tests also showed an increase in inflammatory proteins, as well as metabolic changes linked to chronic conditions, like heart disease and type 2 diabetes.

To make matters worse, their immune cells became less effective at fighting off dangerous pathogens ultimately making them more susceptible to infections.

And to top it all off, even after the participants switched back to their regular diets, some of the negative effects lingered for up to four weeks.

The Tanzanian diet consisted of many fruits and vegetables and less meat (Getty stock photo)

On the flip side, a person who switched to a traditional Tanzanian diet, which consisted of a diet filled with vegetables, fruits legumes, brown rice, whole grains, roots and tubers, as well as fermented foods and partial meat consumption, experienced a reduction in inflammatory proteins and positive metabolic changes in their blood.

According to the study's authors, this is the first study to focus on the health effects of an African diet.

"Previous research has focused on other traditional diets, such as the Japanese or Mediterranean diet." Dr. Quirijn de Mast said (via Science Daily). "However, there is just as much to learn from traditional African diets, especially now, as lifestyles in many African regions are rapidly changing and lifestyle diseases are increasing.

Dr de Mast noted that their experiment showed just how unhealthy and harmful this ‘western diet’ can be for a person's overall health, while highlighting the 'the benefits of these traditional food products for inflammation and metabolic processes in the body'.