About 5,300 years ago, a man, “Otzi,” was trekking high in the Alps and was murdered — dropped where he stood after being shot with an arrow that hit an artery. (One theory suggests the murderer was out for revenge!) Millennia passed and glaciers flowed over the body, perfectly preserving it, until it was discovered by hikers in 1991 and became one of the most important archaeological finds of our time.
Scientists have studied Otzi the ancient iceman’s remarkable remains at length, discovering that he carried freshly sharpened tools, that he was covered in tattoos and that he probably had brown eyes. But it was only recently that they’ve been able to examine his stomach contents: Otzi’s insides had shifted a bit over time, and researchers had difficulty locating the organ. Their findings show that his last meal, just prior to his murder, had an incredibly high fat content — around 50 percent.
“Our body traditionally uses carbohydrate (sugar) stores as energy,” says Amy Shapiro, M.S., RD, CDN, and founder of Real Nutrition. “When our body uses up its carb stores, it turns to fat to burn for fuel — a state called ketosis.”
“Ketogenic diets encourage the body to use fat, instead of carbohydrates, for energy,” Shapiro says. “By depriving the body of carbs, we burn fat, turning it into ketones, which our organs, brain and muscles can use for energy to continue working and maintaining life.” The keto diet calls for food intake comprised of about 70 to 80 percent fat, 15 to 20 percent protein and only about 5 percent carbs.
So with such high fat content found in his stomach, was the iceman considered keto?
While researchers found that Otzi’s stomach contents were about half fat — certainly a high percentage — the other half consisted of a mix of carbs and proteins and a plethora of nutrients. According to Shapiro, he was not keto at the time of his death, but she suspects he may have switched into keto mode occasionally, when in places where fat was most abundant and available. Trekking through the cold, high Alps thousands of years ago, there likely weren’t a lot of carbs to be found, and he likely helped maintain his energy by eating — and burning — fat.
“His high-fat diet was probably (the result of) what was available to him during his trek and in those weather conditions,” Shapiro says. “Many grains and greens were likely not in bloom, and animal fat — which was more available — made up most of his diet. Because he had a mix of nutrients in his gut, it’s likely he ate what he could find seasonally.”
Shapiro points out that more research is needed, but there appears to be some clear benefits to going keto. “It helps with weight loss, stabilizing blood sugar levels and maintaining hormone levels,” Shapiro says. “Additionally, it’s been used to help control Parkinson’s and epilepsy in children.”
One huge argument against keto is that it cuts out almost an entire food group — carbs — which includes not only grains, but also some vegetables. “Many important nutrients [are eliminated], and the diet may not be sustainable long-term,” Shapiro says.
Although not strictly keto, Otzi’s last meal has provided scientists with a window into our ancestors’ diets, and they’re not all that different from diet trends of today.