Why fatty foods don’t let you stick to your diet
Fatty foods may damage the region of the brain responsible for regulating a person’s appetite, which could account for why obese people often find it difficult to stick to a diet, scientists have revealed.
A study has found that a diet rich in saturated fats leads to the sort of damage to the brain’s hypothalamus that would normally be seen during ischaemic stroke, when the nerves are starved of oxygen.
“The hypothalamus is a small area at the base of the brain containing neurones that control the amount of food we eat and the energy we expend,” the Independent quoted Lynda Williams of the Rowett Institute for Nutrition and Health at Aberdeen University, as telling the British Science Festival.
“However, this control breaks down in obesity – the system appears not to work – and we don’t really know why this happens,” she said.
To help answer the question she used a strain of mice that is susceptible to weight gain and put half of them on a high-fat diet, and the other half on a normal low-fat diet.
After just three days they saw changes to the proteins [of the hypothalamus], and to the genes after one week.
“Our experiment reveals a potential mechanism whereby a high-fat diet that is energy dense can damage or injure the hypothalamus,” she said.
“These changes may lead to the break down of the energy-balance centres in the brain, and so encourage weight gain and obesity.
“I’m almost sure it’s a direct effect of the fats on the brain. One of the first things that happens to the hypothalamus early on in high-fat feeding is that it become insensitive to [appetite hormones], so there is a sort of global loss of control of appetite,” she added.