Lore of Nutrition: Challenging conventional dietary beliefs

by Tim Noakes

‘Nature makes foods either fat- or carbohydrate-based. Rarely does it put the two together,’ she said. It is therefore unhelpful to set targets for macronutrients because, inevitably, when you set a limit of 30 per cent fat, you also set the recommendation of 55 per cent carbs. Instead, Harcombe said it would be more helpful if experts gave the same advice that Noakes gives: ‘Just tell people to eat real food.’ Harcombe’s armoury for undermining the evidence-base for ‘conventional’ dietary advice in South Africa was extensive. She used data from her meta-analysis published in Open Heart in 2015 to show that there was no evidence from RCTs at the time the US government introduced its guidelines to 264 million Americans.4 There was still no evidence when the UK and most other English-speaking countries, including South Africa, slavishly followed suit. The UK essentially did a ‘U-turn in dietary guidelines’, Harcombe said. In 1969, the advice was to avoid fattening farinaceous (starchy) foods. In 1983, people were told to base their meals on these foods.