For something that doesn't contain any calories, TV sure is "fattening". Every two hours spent in front of the television increases your risk of becoming obese by 23 percent, according to a Harvard study. And that applies to all women regardless of physical activity levels. That means even if you exercise regularly, TV can be contributing to weight gain.

But how? It's the things that we do -- or don't do -- while watching TV that's largely responsible for the expanding waistline:

You become a couch potato

No news in that. You're basically laying around watching the tube rather than exercising. When you're inactive, you're not moving those muscles that will help raise your metabolic rate and burn more calories.

You eat more in front of the TV

People who watch television are also more likely to consume unhealthy snacks and drinks -- especially energy-dense snacks, drinks and fast food -- and eat less fruit and vegetables, says a Loughborough University study which explores the TV-diet link.

"For some people, a substantial proportion of their daily energy intake is consumed whilst watching TV," says co-author Professor Stuart Biddle. If you have the habit of eating in front of the TV, "television can also act as a distraction, resulting in a lack of awareness of actual food consumption or overlooking food cues that may lead to overconsumption."

You're tempted with junk food adverts

The commercials don't help either. Television viewers are exposed to numerous advertisements that can influence the type of food they desire and consume, adds Professor Biddle. The more you watch commercials promoting high-calorie high-fat foods, the more you're subconsciously primed to crave them. And the next thing you know, you're marching into the kitchen to grab a big bag of chips or a tub of Ben & Jerry's -- even when you're not really hungry.

Make TV less "fattening"

So if you love nothing more than watching the prime-time line-up, what can you do to make television less detrimental to your waistline? Here are some strategies:

Move more often. Multi-task as you're watching your show by doing lunges, squats or getting on the treadmill to burn extra calories. During commercial breaks, get up to move around, clean the dishes, water the plants, etc.

Don't eat your dinner in front of the TV. Practise 'mindful eating' by having your meals at the dining table and focus on eating without any distractions, so you can listen to your body's cues that you're full.

Have healthy snacks on hand. Make smarter snack choices at the supermarket by going for wholesome bites such as apples, celery sticks, raisins, berries and unsalted nuts. Don't buy fattening cookies, chips and ice-cream home, and you won't be tempted to reach for them when you watch TV.

Cut down on TV time. You don't have to give up on your favorite shows; just take a break on days when the programme has nothing interesting, and do something other than parking on the sofa -- like taking an evening stroll or catching up with an old friend.