On a diet? Then consider sitting by the window the next time you eat out.

A new book claims that where you sit in a restaurant can affect how many calories you consume.

The researchers measured and mapped the layout of each restaurant and then used meal checks to track what diners ordered and how it related to where they sat.

The results were telling: people sitting farthest from the front door ate the fewest salads and were 73 per cent more likely to order dessert.

Those seated at a dark table or booth ate heavier food and ordered more of it, while diners seated at high-top bar tables ordered more salads and fewer desserts.

'The darker it is, the more "invisible" you might feel, the less easy it is to see how much you're eating and the less conspicuous or guilty you might feel,' Professor Wansink explains in the book.

In contrast, 'seeing the sunlight, people or trees outside might make you more conscious of how you look, might make you think about walking or might prompt a green salad.'

And if there are TV sets in the restaurant, steer clear. Professor Wansink found that the closer a table was to a screen, the more fried food the diners ordered.

The researchers also noted that slim diners chewed around 15 times per mouthful, three chews more than heavier diners. By eating more slowly, the diner consumes less in the time it takes for the brain to register satiety.