These twins followed different diets for 12 weeks. The results are shocking.

For decades, the fitness community has been torn: is high-fat or high-carb the ultimate fuel?A recent experiment put the age-old debate to the test using a pair of identical twins who share 99% of the same DNA.The results might surprise you.By the end of the 12-week experiment, both Ross and Hugo Turner, 36-year-old professional adventurers from the UK, were fitter and leaner — but one brother had noticeably more energy than the other.For the experiment, the twins ate three meals and two snacks per day from a food delivery service, Frive, plus 350-calorie protein shakes.

Their daily intake totaled about 3,500 calories, according to Business Insider.Hugo went low-carb, adding high-fat foods like olive oil, butter, nuts, eggs, and avocado to his Frive meal plan.

Meanwhile, Ross stuck to a more “balanced” plan, loading up on carbs like pasta and rice and avoiding fats.The Turners also followed similar workouts — cardio and strength training with home gym equipment — and rested every three days.Their progress was monitored by sports scientists at the University of Loughborough.After 12 weeks on the high-carb diet, Ross gained 2.2 pounds of muscle, lost 2 pounds of fat, improved his cholesterol levels, and reduced his internal visceral fat from 11.5% to 11.1%.Hugo gained 6.6 pounds, lost just 0.6 pounds of fat, saw no change in his cholesterol, and increased his visceral fat from 11.4% to 12.6% after following the high-fat diet.Visceral fat is the dangerous fat stored around internal organs, linked to chronic diseases like heart disease and type 2 diabetes.The brothers, both already strong and fit before the experiment, also tested their physical ability after 12 weeks.

While both saw nearly identical results in strength tests, Hugo struggled with cardiovascular fitness and endurance following the high-fat diet.“I just never felt good,” Hugo told Business Insider.“I was eating at least six times a day and never felt full or satisfied, hence I was cons...