For some of us, it is just the sight of food. See it, want it, eat it.

Advertisers benefit from this by showing us appetising foods with lots of happy people enjoying them. TV food advertising has been shown to make us eat significantly more of anything. Just watching the ads makes us rush to the cupboards. This sort of eating is not related to meals. It tends to be hand food - biscuits, crisps, sweets. And it is eaten without much thought - hand, mouth, hand, mouth. This sort of eating is called automatic eating. You scarcely know how much you have eaten. In fact, we look into the crisp packet and are astonished the

Researchers conducted 2 experiments. First, children aged 7-11 watched a cartoon including food ads. They ate 45% more snack food while watching the show than children who watched the same cartoon with non-food ads.

They show that just half an hour a day watching telly the would lead to a weight gain of nearly 10 pounds a year (we are talking about children here) unless they cut down their other calorie intake or increased their physical activity.

In a second experiment,adults watched TV interspersed with snack food ads. They ate significantly more than those who saw ads with a nutritional or healthy food message. These effects persisted even after the TV viewing.

Adults and children increased eating of any foods in the house, not just those advertised.

“This research shows a direct and powerful link between television food advertising and calories consumed by adults and children,” said Jennifer Harris, PhD, the study’s lead author and director of Marketing Initiatives at the Rudd Center. “Food advertising triggers automatic eating, regardless of hunger, and is a significant contributor to the obesity epidemic".

What to do about this if you are wanting to control your weight? Watch less telly. Don't always have snack foods in the house to tempt you when the ads give you the munchies.

I have said before that exercise will not really help in losing weight. Exercise is good for its own sake as it maintains your health and makes you feel good (so you might eat less). Cutting down by 250 calories a day is much easier than exercising it off.

Indeed, you may have noticed that you consider walking to the bus stop with the goal of exercising away that chocolate bar. Wishful thinking because to work off 4 ounces of Cadbury’s Dairy Milk needs you to walk 5 miles (10,000 steps) at a fast pace.

We often make mistakes about weight control strategies. For example, drinking diet fizzy pop doesn’t help us reduce weight. We tend to compensate for it by eating something else, taking the view that diet pop is the diet!

But doing nothing and lying about is generally a bad thing.

Peter Katzmarzyk and colleagues at the Pennington Biomedical Research Center examined the links between time spent sitting (at school, work, and at home) and mortality (death) in a representative sample of more than 17,000 Canadians. They report that time spent sitting was associated with increased risk of all-cause and cardiovascular disease mortality (there was no association between sitting and cancer death). Individuals who sat the most were about 50% more likely to die during the follow-up period than individuals who sat the least, even after controlling for age, smoking, and physical activity levels.

The researchers also examined the association between sitting and mortality after control for body weight in some cases. They report that sitting remains a significant predictor of mortality. This suggests that all things being equal (body weight, physical activity levels, smoking, alcohol intake, age, and gender) the person who sits more is at a higher risk of death than the person who sits less.(Fidgetting has been shown to be an effective strategy. So don’t listen when people tell you to stop!)

Most of us are sedentary throughout the work day and so most of us are at risk. And at home too, we spend little time working in the kitchen, cooking, laying the table, washing up. Even in front of the telly we don’t get up to change the channel. Our whole environment seems to be geared to minimising effort.

What to do? Throughout the day to move about and fidget as much as possible. Seek out opportunities to make more effort. Walk whenever possible.