Added sugar in our diet is a very recent phenomenon and only occurred when sugar, obtained from sugar cane, beet and corn, became very cheap to produce. It’s a completely unnecessary part of our calorie intake: it has no nutritional value, gives no feeling of fullness and is acknowledged to be a major factor in causing obesity and diabetes both in the UK and worldwide.

Can poor people afford the latest high fat, low carb diet that's taken popular root among South Africa's middle classes? A community service doctor in Mpumalanga challenged herself to a two-week 'Bant' on the budget of a poor rural South African ie on only R150...