There's still time to catch up and see 'The Truth About Slim People', Channel 4, 8th November. A programme about weight loss that's a bit more science based for a change!
Two slim individuals were followed around to see how they did it and for those who don't have time to see for themselves the highlights were.....
The participants had a low alcohol intake (an obvious one).
They didn't eat late in the day.
Their diet was auto-balancing. In other words, times of excess were instinctively followed by corresponding periods of deprivation. Eating was primarily a response to stomach, not mouth hunger.
The researcher's resting metabolic rate was measured by monitoring respiratory CO2 emissions, correlating with energy use, and found to be typical at 1500 calories per day.
Eighty consecutive days of 100 calorie excess would cause weight gain of 1 kilo ( 2.2 pounds).
(The statistic I prefer is a 140 calorie excess would cause weight gain of a stone in a year)
Fidgets use more energy and those who sleep longest are more likely to be slimmer.
For me, the most interesting part described an experiment involving 80 participants who were given a small salad to eat. Half were told it was a snack, half that it was a meal. When subsequently shown into a room with more food and instructed to carry out a diversionary task, those who had been given a 'snack' ate twice as much as those who had received a 'meal'.