Dietary fats

If minimising fat intake was yesterday’s advice how does fat fit into an athlete’s diet today?

he nutrition world is constantly changing; as science advances, advice and guidelines swiftly become outdated and obsolete. Dietary fats are a case in point.

Conventional wisdom has it that an endurance athlete’s diet should comprise 60-70 per cent carbohydrate, 15 per cent protein and the remaining 15-25 per cent fat. Optimal nutrition is not quite so simple; it is not only the proportion of fat that matters but also the type, according to Barry Murray of Optimum Nutrition 4 Sport, who has worked with the BMC and Orica-scott teams.

“You need to consider the term ‘healthy fats’. For a long time, healthy fats were deemed to be those that were low in saturated fats — sunflower oils, vegetable oils or spreads,” he says.

This principle has now been called into question, explains Murray.

“It turns out that these so-called ‘healthy’ fats are very oxidisable, meaning they are unstable during cooking and may release free radicals, which can cause inflammation.”

Murray believes saturated fats are more stable and therefore preferable.

“My riders are now cooking with butter and eating full-fat Greek yoghurt. Some are even cooking with lard and duck fat and things like that.”

Trent Stellingwerff, director of performance solutions at the Canadian Sport Institute Pacific, has investigated the nutritional strategies required to optimise training and racing for middledistance runners. His research found that, at certain times of the year, such as during the competition phase, fat intake may be limited without harm to reduce total energy intake to achieve body composition goals. However, the study also confirmed some dietary fat is needed throughout the year to aid the absorption of fat-soluble vitamins.

Stellingwerff admits that the matter is not settled; current scientific knowledge is not definitive.

“Our understanding of the impact that fat has on health, let alone performance, is still emerging,” he says. “Secondly, what athletes think they consume is a lot different to what they actually consume. You can’t sum up the matter briefly; tweets about dietary fat, for instance, don’t do justice to the complexity, and tend to massively confuse and complicate the perception of this topic.”