ISLAMABAD (Online): For years we were told the secret to staying slim and healthy was a low fat, low calorie diet.But the tide has begun to turn – and the countless products claiming to be ‘light’, ‘lean’ or ’99 per cent fat-free’ are becoming increasingly demonised.
Instead, fat is our new friend – provided we eat the right type.
Here, writing for The Conversation, nutrition expert Rebecca Charlotte Reynolds reveals what we should be eating:
First, let’s talk about fat.
Fat in foods and drinks is either unsaturated (monounsaturated or polyunsaturated, the latter as omega-3 or -6), saturated or trans-saturated (trans-fats).
These differ based on their chemical structures and properties, including whether they are ‘saturated’ with more hydrogen molecules and are liquid or solid at room temperature.
They also differ in their effects on human health.
The experts’ advice has included care with total fat intake, avoidance of saturated and trans-fats and a mostly monitored consumption of ‘healthier’ unsaturated fats.
In the early to mid-1900s, discoveries about the energy value of different macronutrients led to the establishment of ‘Atwater Factors’.
These are standardised values of how much energy, or kJ/kcal/calories, a nutrient such as fat or carbohydrate provides to the human body.
Fat was assigned the highest value of 37 kilojoules per gram, indicating it provides the most energy per weight unit (gram) to the human body out of all the macronutrients (more than carbohydrates, protein and alcohol).
As it was the most energy-dense, this contributed to a belief that a high-fat diet would lead to weight gain.