I am currently reading Men's Fitness, & an article in there was entitled 'Should I Eat After 8pm?', now the chap who said "No" brought up some interesting points to which I shall not bore you with, but he did come out with an old maxim 'Breakfast Like A King, Lunch Like A Lord, & Dine Like A Pauper', to which we shall come to.
However, on the "Yes" side was a woman who is Chief Scientific Officer for Weightwatchers, this is what she said -
"It's the number of calories you consume over the course of a day, not the hour of the day you eat, that contributes to weight gain. A swedish trial found that people given meals after 8pm burned the same number of total calories as those who were fed three meals before this time.
There are some behaviourial reasons why people link weight gain to eating late. If someone who normally snacks in the evening suddenly stops then they will probably lose weight - but this is because total daily calorie consumption is lower, not because of the time factor. Our bodies aren't machines that turn on or off: we're constantly burning calories to stay alive. Your metabolism may slow down at the end of the day but not by enough to make a difference to weight gain. The bottom line is that a calorie is a calorie, no matter what the clock says.
Humans are creatures of habit. They come in from work and switch off with some sort of 'treat', but forget to include these calories in their daily allowance. If you are prone to sitting in front of the TV with a bowl of ice cream or a packet of crisps, then it may be worth putting a restriction on what time of day you eat, or make sure these calories are accounted for in your daily allowance." (Karen Miller-Kovach 2009)
Now I have always admired the old maxim 'Breakfast Like A King, Lunch Like A Lord, & Dine Like A Pauper' as on the previous Weightwatchers diet (& this one) I have followed that ideal.. It is because it is so simplistic in its approach, & I did lose weight with it.
The interesting thing about this is valid points have been made, that a) we are creatures of habit, b) a calorie is a calorie, no matter what the clock says & c) dine like a pauper, if you are unsure.