Vegan and meat-based diets were put to the test by a pair of identical twins to see which was the best.
All in the name of research, charitable causes, and exploration, the Turner twins have climbed a mountain and trekked to the most inaccessible points on every continent. Hugo and Ross Turner’s latest adventure took them into even more dangerous territory, comparing the effects of a vegan diet versus an omnivorous diet on two genetically identical people.
The pair took part in a 12-week study with Kings College London and ate the same amount of calories every day.Hugo abstained from meat and dairy, while Ross supplemented his diet with fish, and they even went to the same gym.
From January to March of this year, the Turners decided to compare and contrast the two eating styles during a 12-week fitness training program. According to Ross, they were inspired by the growing popularity (and sometimes controversy) of vegan diets for athletes, as a result of documentaries like “The Game Changers.”Hugo admitted that transitioning to a plant-based diet wasn’t easy at first, but he eventually felt more energized.
“We wanted to take bias and opinion out of it and take down to the genetic level. We can get science involved because we’re twins and genetically identical, so we can compare ourselves in extreme environments,” Ross told Insider.
Throughout the experiment, the couple kept track of how they felt and were followed by researchers from King’s College who tracked basic health metrics like weight, cholesterol, and muscle mass.
Both twins went to the gym five to six times a week to do endurance training, following a program devised by Ross, a personal trainer. They also consumed nearly identical amounts of calories in meals delivered by the Mindful Chef service.
They noticed significant differences in muscle gain, fat loss, and digestive health by the end.
Hugo weighed 185 pounds and had 13 percent body fat prior to the experiment when he gave up animal products. He claimed to have lost nearly nine pounds after a month on the vegan diet. He weighed 181 pounds at the end of the experiment. Almost all of the weight he lost was fat mass, with his overall body-fat composition dropping a full percentage point to 12%. His cholesterol levels decreased as well.
His energy levels were even more impressive. Hugo claimed that his lunchtime gym sessions made him feel significantly more alert than his usual routine.
“On a vegan diet my mental focus was much better, I didn’t have the mid-afternoon energy dips, and felt a bit more charged,” he told Insider.
One explanation, he said, could be how his snacking habits have changed as a result of his vegan diet. He’d switched to mostly fruit and nuts because biscuits and chips aren’t vegan.
Hugo did notice one exception to his increased energy levels: a sharp drop in his libido.
“I just lost it — I have no idea what happened,” he said, adding that his experience may not be representative of all people.
Blood tests were not done during the experiment, but the twins said they would do so if they tried something similar again. They could, for example, measure testosterone to see if it explains some of the changes.
He continued, ” I think the first couple of weeks it was really craving and wanting meat and dairy and cheese. I love cheese.
“I was now having to eat fruit and nuts and alternatives that didn’t have any dairy in them.
“I was eating a lot more wholesome food, which meant that my sugar levels were a lot satiated during the day. I felt more energetic.”
Meanwhile, his meat-eating twin admitted that his gym performance was “a little bit more up and down.”
Ross has always been the slightly larger of the two brothers, and the experiment only added to that. He gained 10 pounds of muscle and lost just over four pounds of fat after starting at 13 percent body fat. His overall body fat percentage increased slightly to 15%, and his final weight was 189 pounds.
Throughout the 12-week period, his cholesterol levels remained stable.
Ross said the meal plan for this experiment was slightly more varied than his regular diet and extremely well-balanced in terms of macronutrients, featuring a variety of chicken, fish, red meat, vegetables, dairy, and grains.
Previously, the twins’ daily diet consisted of toast or porridge for breakfast, sandwiches for lunch, and some variation of chicken, vegetables, or pasta for dinner.
The vegan diet also had a significant impact on the gut microbiome.
Hugo’s dietary change was even more significant, as tofu, tempeh (fermented soybeans), and jackfruit were substituted for his usual animal-based protein.
“When you eat a vegan diet, you almost have to compensate for the lack of variety with variety, so I was eating foods I wasn’t used to,” Hugo explained.
As a result, according to fecal samples analyzed by Atlas Biomed before and after the experiment, his gut microbiome — the populations of beneficial bacteria that live in the human digestive system — changed in some interesting ways.
According to the analysis, the changes improved Hugo’s resilience to some forms of chronic illness, lowering his risk of obesity and type 2 diabetes. This research backs up previous findings that plant-based diets can lower the risk of these diseases by improving the microbiome.
But, to their surprise, both brothers’ microbial diversity, or the number of different bacteria species in their gut, decreased. This has been linked to a lower level of resistance to chronic illnesses like Crohn’s disease.
Ross’ microbiome changed slightly, but it remained far more stable than his brother’s.
It’s unclear why those changes occurred, though the Turners speculated that the abrupt switch to a vegan diet, as well as the experiment’s short duration, may have played a role.
The Turners intend to include more vegan foods in their regular diet, particularly snacks.
One limitation of the study, according to the Turners, was that 12 weeks isn’t a long time for a typical dietary study. If they could do it all over again, the brothers say they’d try the diets for six to a year to get more data.
The brothers, on the other hand, say they’ve learned a lot and plan to eat more plant-based foods in the future. The brothers are well-known for their endurance treks, and they want to see if vegan eating will help them on their journeys.
“You lose about half a kilo of weight a day on an endurance trip, more than that if you’re carrying extra weight, so we like to be lean and mean nothing in between on the trip,” Hugo said.
He added that being forced to find vegan alternatives also greatly expanded his world of food options.
“One thing to come out of this is we don’t eat nearly enough variety of foods. Often, we kind of just disguise the same foods in different forms,” Hugo said. “But variety is the spice of life.”