Change occurs in weeks London - Arabstoday High-fat diets pile on weight around the midriff - but in mice at least, they also seem to cause 'growth' inside the brain. Sadly, a diet of cheeseburgers won't make you more intelligent - the new cells trigger weight gain. Mice with the new cells packed on weight far faster than other mice - even when both were on the same high-fat diet. The finding could offer an insight into how the brain controls weight gain through eating and hunger. It could even open new avenues into understanding the factors that trigger obesity. It's not clear whether the same process is at work in humans - but if so, the finding could also offer an avenue for anti-obesity treatments. 'This kind of work will definitely inform how we think about the underlying factors that relate to obesity,' said endocrinologist Jeffrey Flier of Harvard Medical School in Boston in an interview with Science Now. 'That is going to be a very interesting frontier.' The research found that a high-fat diet caused nerve cells to grow in a tiny part of the brain called the median eminence. Mice who ate a high-fat diet also gained large numbers of cells in the median eminence, creating up to four times as many as mice with a normal diet - and the change occurred in weeks. Mice with more of the cells gained more weight, thanks, the researchers think to a mysterious type of brain cell called a 'tancyte' - which is also found in humans. Lead researcher Seth Blackshaw of John Hopkins University said, 'This is the very first step in trying to understand this process. We're a long way from realising whether this is relevant to human obesity.'