BOSTON — Lawmakers on Beacon Hill are joining activists in other states pushing for taxes on sodas that they say will ease the rise in obesity-related diseases and bring in money for programs aimed at improving the health of children in Massachusetts.

Supporters of the tax say that too many children and families in Massachusetts are suffering from chronic diseases like Type 2 diabetes, heart disease, stroke, cancer and tooth decay.

They say that the single largest source of added sugar in the American diet comes from sugary drinks and cutting down the intake of sugar could ease some of those health concerns.

“The goal of this legislation is to reduce the consumption of sugary drinks replacing it with water and other healthier beverage choices, particularly among children and teenagers,” said Democratic state Sen. Jason Lewis, one of the sponsors of the legislation.

The bill would set up a tiered tax rate based on the amount of added sugar per 12 fluid ounces of a drink over 5 grams.

Beverages with between 5 and 19 grams of sugar per 12 fluid ounces would be taxed at one cent per ounce. Beverages with 20 or more grams per 12 fluid ounces would be taxed at 2 cents per ounce.

A 12-ounce can of Mountain Dew, for example, contains 46 grams of sugar and would cost an extra 24 cents under the bill.

The Harvard School of Public Health estimated the bill could raise about $368 million annually in Massachusetts, according to Lewis. He said the bill proposes that the money be deposited in a newly established Children’s Health Promotion Fund that would be administered by state Department of Public Health.

“This will improve health, lower rates of preventable, chronic diseases and reduce health care costs over time,” Lewis said.

The Massachusetts Beverage Association, which represents the soft drink industry, opposes the proposed tax.

“There are much better ways to fund programs important to our communities than a tax that threatens jobs, hurts our local businesses and hits working-class families the hardest,” the Massachusetts Beverage Association said in a statement.

Republican Gov. Charlie Baker also isn’t a fan of the idea.

“I don’t think we should be raising taxes and I’ve said that before, especially not a tax that basically hits low-income people a lot harder than it hits everybody else,” Baker said Wednesday.

But backers of the bill said that poor and minority children are at a higher risk of over-consuming sugary drinks with black children on average seeing twice as many advertisements for soda every day as white children.

After Berkeley, California, imposed a 1 cent per ounce tax on sugary drinks in 2015, consumption fell by more than 20 percent in low-income communities in the first four months while water consumption increased, Lewis said.

A tax on sugary drinks isn’t a new idea in Massachusetts.

Former Democratic Gov. Deval Patrick pushed unsuccessfully to apply the state’s 6.25 percent sales tax to candy and soda, a proposal he said would have raised more than $60 million annually for the state.

Cities across the country have weighed similar soda taxes.

Voters in Santa Fe, New Mexico, rejected a tax increase on sweetened beverages earlier this month, handing a rare victory to the soft-drink industry after recent defeats.

A string of taxes on sugary beverages won approval last year from Philadelphia and the California cities of San Francisco and Oakland.