Adults and children should consider having TV-free days or limiting viewing to no more than two hours a day under new proposals to tackle obesity.
The National Institute for Health and Care Excellence (NICE) recommendations also include avoiding drinks with added sugar and limiting takeaways.
The draft guidance, the first on the subject since 2006, is aimed at helping people maintain a healthy weight.
Obesity rates nearly doubled over the past 10 years in England.
Prof Mike Kelly, director of the Centre for Public Health at NICE, said a healthier diet and being more physically active was important for everyone, not just those who were already overweight or obese.
"The general rule for maintaining a healthy weight is that energy intake through food and drink should not exceed energy output from daily activity," he said.
"We all know we should probably take the stairs rather than the lift, cut down on TV time, eat more healthily and drink less alcohol.
"But it can be difficult to know the most useful changes that we can make in terms of our weight."
The guidelines make a number of recommendations that aim to ensure the advice given about maintaining a healthy weight is more specific and based on real evidence.
There are also new recommendations encouraging people to monitor their weight and activity levels, using apps or regular weigh-in sessions.
The draft suggestions include:
- Walking or cycling to school or work
- Reducing TV viewing with strategies such as TV-free days or setting a limit of no more than two hours a day in front of the TV screen
- Cutting down on calorific foods, such as fried food, biscuits, sweets and full-fat cheese
- Adopting a Mediterranean diet high in vegetables, fruit, beans and pulses, whole grains, fish and olive oil
- Avoiding drinks sweetened with sugar, including fizzy drinks, sports drinks and squash
- Limiting the amount of fast food and takeaways
- Limiting the amount of alcohol consumed, as alcoholic drinks are a source of extra calories
Last month, health leaders called for an emergency taskforce to be set up to tackle childhood obesity in England.
In an open letter to the chief medical officer for England, Prof Dame Sally Davies, they said "an entire generation is being destroyed by a diet of junk food and sugary drinks".
And last week, the head of NHS England, Simon Stevens, said obesity was "the new smoking" in terms of the impact on health and the cost to the NHS.
A quarter of adults - up from 15% 20 years ago - and one in five schoolchildren is obese, figures show.