... GUILT FREE
We just keep getting heavier. Today around 40 per cent of all adults are overweight or obese and every single nation on Earth is getting fatter. Obesity-related diseases, such as type 2 diabetes, are soaring on a trajectory that will cripple many health services. Most troublingly, there have been no success stories in the past 33 years – not one country has been able to halt the growth of the bulge. Processed, calorie-dense foods continue to become more widely available worldwide and, short of an international catastrophe like a global famine or mass outbreak of war, turning the tide is going to take some truly innovative thinking.
A short-term solution is to re-engineer calorific ‘junk’ food to have less fat, sugar, salt and fewer calories, while still giving the same satisfaction. There are artificial sweeteners, but they can have unpleasant side effects and can’t be cooked as sugar can. Low-calorie sugar substitutes, such as sugar-alcohols like sorbitol, taste like the real thing but cause flatulence and diarrhoea if eaten excessively. But food technologists have managed to coat inert mineral particles with sugar, increasing the surface area that contacts the tongue, so that less sugar can be used to provide the same sweetness.
In the longer term, fine-tuning our biology could allow us to eat without guilt. Few people realise that our appetite is precisely regulated. Overeat on a Monday, and you usually eat less on Tuesday and Wednesday. Our hunger is usually set to a level almost identical to the number of calories we need. Unfortunately, the hunger ‘thermostat’ is set a little too high, by an average of about 0.4 per cent (or 11 calories a day). Left to our own devices, we will each tend to eat an extra peanut’s worth of calories each day. That doesn’t sound like much, but it adds up to nearly half a kilogramme weight gain each year. Our unfortunate tendency to develop ‘middle-aged spread’ has presumably evolved as an insurance against the next famine.
The hunt is on to nudge the appetite set point down by 11 calories or more. Many hormones swirl around the blood to tell us when to eat and when to stop. One hormone, CCK, is released by the gut when food enters it, making us feel full. Another hormone, leptin, is released by body fat and apparently tells the body when our fat stores are adequate. It’s a complex picture and attempts at manipulating individual hormone levels have been unsuccessful. Everyone is hoping that we will soon untangle the web of brain hormone messages and managed to devise supplements, foods or medicine that can make a tiny tweak to the dial.