Replacing fats with high carbohydrates worse for health

The study published in The Lancet on 29 August 2017, is being presented at the European Society of Cardiology Congress 2017 and involved more than 135 000 people from 18 countries.

High fat diets, lower risk of mortality

It was found that high fat diets (about 35% energy – including both saturated and unsaturated fats) were associated with a lower risk of mortality, whereas a high intake of carbohydrates (above 60% energy) was associated with a higher risk.

Saturated fats are typically found in animal fat products, like milk and meat, while monounsaturated and polyunsaturated fats are typically found in vegetable oils, olive oils, high fat fruits like olives and avocados, nuts and fish.

The study found that, on average, globally, people’s diets consisted of over 60% energy from carbohydrates and 24% energy from fats, suggesting that, rather than focusing on reducing fat intake in diets, guidelines should instead focus on reducing carbohydrate intake.

Low fat diets, higher risk of mortality

Additionally, while current guidelines recommend reducing saturated fat intake to below 10%, the study found that very low intake of saturated fats (below 3%) was associated with a higher risk of mortality, compared to diets with a higher intake of saturated fats of up to 13%.

“The current focus on promoting low-fat diets ignores the fact that most people’s diets in low and middle income countries are very high in carbohydrates, which seem to be linked to worse health outcomes.

“In low- and middle-income countries, where diets sometimes consist of more than 65% of energy from carbohydrates, guidelines should refocus their attention towards reducing carbohydrate intake, instead of focusing on reducing fats,” says lead author Dr Mahshid Dehghan, McMaster University, Canada.

Best diet is 35% total fat

The best diets will include a balance of carbohydrates and fats – approximately 50-55% carbohydrates and around 35% total fat, including both saturated and unsaturated fats,” continued Dr Dehghan.