We all know that diet is extremely important to our health but with so much conflicting advice it's hard to know which diet will give the best results.
You would expect that all the major diets had been rigorously compared by health academics, but Dr David Katz, a physician and researcher from Yale University's Prevention Research Centre, said that comparisons are limited, so he looked at all the medical evidence.
"There have been no rigorous, long-term studies comparing contenders for best diet laurels using methodology that precludes bias and confounding," he told The Atlantic.
Dr Katz and his team compared low carb, low fat, low glycaemic, Mediterranean, mixed/balanced (DASH), Paleolithic, vegan and elements of other diets.
While he found none to be clearly the best, he discovered common elements that would promote good health outcomes.
What the evidence says
Eat lots of fruit and vegetables, whole grains, nuts and seeds and limit your intake of processed foods.
"A diet of minimally processed foods close to nature, predominantly plants, is decisively associated with health promotion and disease prevention," Dr Katz said.
Dr Katz also found no evidence that low fat diets are better than higher fat diets, such as the Mediterranean, which is higher in "good fats", such as olive oil and nuts.
However the Mediterranean diet, which is high fibre, and allows moderate alcohol and meat does appear to help ward off heart disease, cancer, obesity and metabolic syndrome.
"It is potentially associated with defence against neurodegenerative disease and preservation of cognitive function, reduced inflammation, and defence against asthma," Dr Katz said.
Quick fix diets are bad
He likened quick fix diets to junk food, and said all health conscious people need to do is eat foods as close to nature as possible.
"If you eat food direct from nature, you don’t even need to worry about trans fat or saturated fat or salt – most of our salt comes from processed food, not the salt shaker," he said.
"If you focus on real food, nutrients tend to take care of themselves."
The research was published in the Annual Reviews.