Three golden rules for a healthy diet
Which one wins – a healthy low-fat diet or a healthy low-carbohydrate diet?
When it comes to weight change, neither apparently.
The study, published in the Journal of the American Medical Association (JAMA) has found no significant difference between the two diets even after being on them for 12 months. It also found no relationship between weight fluctuation and a participant’s DNA testing.
Importantly however, the study did find that people who cut back on added sugar, refined grains and highly processed foods while concentrating on eating plenty of vegetables and whole foods — without worrying about counting calories or limiting portion sizes — lost significant amounts of weight over the course of a year.
Professor Christopher Gardner, the Director of Nutrition Studies at the Stanford Prevention Research Center who led the study, said there is no single diet that fits everyone.
“I continually see three factors that come up again and again: get rid of added sugar; get rid of refined grain; and eat as many vegetables as you can,” Professor Gardner said.
He argues that the study has shown the diet argument is often focused on the wrong things, like which type of diet.
“We are battling points on the fringe of this whole debate without getting to the core,” he said.
The large clinical trial included 609 adults aged 18 to 50 years without diabetes, with a body mass index between 28 and 40, where participants were randomised to the 12-month healthy low-fat diet or a healthy low-carbohydrate diet.
“We really stressed to both groups again and again that we wanted them to eat high-quality foods,” Professor Gardner said.
The low-fat group was told to avoid refined carbohydrates like soft drinks, fruit juice, muffins, white rice and white bread – even though they are low fat. Instead they were advised to eat more nutritionally beneficial foods like brown rice, barley, steel-cut oats, lentils, lean meats, low-fat dairy products, quinoa, fresh fruit and legumes.
The low-carb group was trained to choose nutritious foods like olive oil, salmon, avocados, hard cheeses, vegetables, nut butters, nuts and seeds, and grass-fed and pasture-raised animal foods.
Australia is ranked the fifth highest in the Organisation for Economic Co-operation and Development’s (OECD) latest obesity rankings. Projections show a steady increase in obesity rates until at least 2030. Currently more than one in two adults and nearly one in six children are overweight or obese in OECD countries. OECD adult obesity rates are highest in the United States, Mexico, New Zealand and Hungary, while they are lowest in Japan and Korea.
Speaking on radio recently, AMA President Dr Michael Gannon said the AMA would continue to call for a tax on sugar-sweetened beverages because it is designed to change behaviour.
“We have a situation now where it’s often cheaper to purchase one of these drinks than it is to purchase water,” Dr Gannon said.
Further information about the study can be found https://jamanetwork.com/journals/jama/article-abstract/2673150?redirect=true
AMA’s Position Statement on nutrition was launched earlier this year and is available here: position-statement/nutrition-2018