Families are being urged to ditch sugary drinks and cut down on saturated fat in the latest advertising blitz by England‘s public health watchdog.

Public Health England said a family of four could reduce their sugar intake by three-quarters of a 1kg bag of sugar in just one month by swapping fizzy drinks for healthier alternatives.

Changing whole milk for semi-skimmed milk could mean the average family cutting down their fat intake by a third of a pint over four weeks, the group said.

The advertising campaign, Smart Swaps, is seeking to capitalise on the millions of Britons who begin the new year with health-conscious resolutions after the festive period.

“Swapping like-for-like food in our diet could help cut out surprising levels of saturated fat, sugar and ultimately calories without having to give up the kinds of food we like,” said Professor Kevin Fenton, director of health and wellbeing at Public Health England.

He added: “We all eat too much saturated fat and sugar, which can increase our calorie intake. Together this increases our risk of obesity, cardiovascular disease, diabetes and some cancers.”

Families will be offered vouchers to encourage them to avoid sugary cereals and swap butter and certain cheeses for reduced-fat alternatives.

However, the move brought a backlash from the soft drinks industry. The British Soft Drinks Association (BSDA) claimed its products were being shown in a misleading and “deliberately negative” way.

Gavin Partington, director general of the BSDA, said: “It is particularly frustrating for an industry which has been working with the Department of Health to promote healthier behaviours, reformulate products so they are lower in calories, make available smaller pack sizes and focus more of its marketing investment on low- and no-calorie options.”

He took issue with the depiction in the adverts of a two-litre bottle of pop, claimed to contain the equivalent of 52 sugar cubes.

“It is also disappointing to see our products depicted by the campaign in such a deliberately negative way,” he said. “That two-litre bottle shown in the ad is not intended to be consumed by an individual, certainly not by one child. Such an extreme depiction of the consumption of soft drinks undermines the key message of the campaign, namely that it’s very easy to make a smart swap to a no-calorie, diet soft drink.”

The Children’s Food Campaign welcomed the initiative but said it would be undermined unless supermarkets made healthier foods more affordable and easier to find in stores. The body also said that vouchers offered as part of the Public Health England scheme might not be cheaper than buying own-brand healthy foods.

In a separate study released on Thursday, Cancer Research UK said tripling the tax on cigarettes would cut smoking by a third and prevent 200m premature deaths by the end of this century.

The charity called on governments across the world to raise tax on tobacco, a move it said would encourage smokers to quit and help stop young people taking up the habit.

Harpal Kumar, Cancer Research UK’s chief executive, said: “Worldwide, around half a billion children and adults under the age of 35 are already – or soon will be – smokers, and many will be hooked on tobacco for life. So there’s an urgent need for governments to find ways to stop people starting and to help smokers give up.

“This immensely important study demonstrates that tobacco taxes are a hugely powerful lever, and potentially a triple win: reducing the numbers of people who smoke and who die from their addiction, reducing the healthcare burden and costs associated with smoking and yet, at the same time, increasing government income.”

Meanwhile the cost of joining a gym this year is continuing to rise, according to a Labour survey of 95 local authorities.

Nearly two-thirds of council-run fitness centres have increased the cost of annual membership in the last three years, some by up to £100, the survey found. A yearly gym pass now costs £368 on average, an increase of £15 since 2010, according to the research.

Luciana Berger MP, the shadow public health minister, said there was a desperate need to make leisure facilities affordable for all. “Millions of people across the country will want to kickstart 2014 by getting fitter and more active. There is a real risk however that many people will be put off from keeping to their new year’s resolutions by soaring gym charges and David Cameron’s failure to tackle the cost-of-living crisis.”