The claim is easy to find on google, but here are a few specific examples (emphasis added):

Soda, which is loaded with sugar primarily in the form of high fructose corn syrup, is a leading contributor to the rising rates of obesity, diabetes, heart disease and other chronic diseases facing Americans.

 

So when I say that drinking a can of soda is just as bad for you as smoking a cigarette (and maybe even worse) it is not an exaggeration.

 

Source: here and here.

Also:

Research on the health effects of drinking soda have been popping up everywhere in past few years. Some even claim that drinking soda could be as dangerous to our health as smoking cigarettes. Is soda the new cigarette?

 

Source

Subtitle of this article:

#The Case Against Soda ##Why the sweet stuff might be as bad for your health as smoking or drinking excessive alcohol.

And the title of this article:

#Drinking Soda Is Now as Bad as Smoking

It appears to me that the first links are looking at aggregate statistics, and from this drawing the conclusion that the overall harm to our society's health is greater from sodas than from smoking. I am willing to accept that this may indeed be true. But the articles all appear to be making a much different claim, that:

##On an individual basis, or perhaps on a per-serving basis, drinking a soda is more harmful than smoking a cigarette.

Is there any validity in this claim?

Considering that the types of harm inflicted by each substance is different, I'm open to suggestions on how to best compare the two. Two proxies I can imagine for comparing the two might be:

1. Given a habitual smoker who smokes N cigarettes per day, compared to a soda drinker who also consumes N fizzy drinks per day, who is likely to have the higher medical bills from chronic disease?

2. Drinking N sodas reduces a person's life expectancy by an amount equal or greater than the smoking of N cigarettes.

The claim is easy to find on google, but here are a few specific examples (emphasis added):

Soda, which is loaded with sugar primarily in the form of high fructose corn syrup, is a leading contributor to the rising rates of obesity, diabetes, heart disease and other chronic diseases facing Americans.

So when I say that drinking a can of soda is just as bad for you as smoking a cigarette (and maybe even worse) it is not an exaggeration.

Source: here and here.

Also:

Research on the health effects of drinking soda have been popping up everywhere in past few years. Some even claim that drinking soda could be as dangerous to our health as smoking cigarettes. Is soda the new cigarette?

Source

Subtitle of this article:

The Case Against Soda

Why the sweet stuff might be as bad for your health as smoking or drinking excessive alcohol.

And the title of this article:

Drinking Soda Is Now as Bad as Smoking

It appears to me that the first links are looking at aggregate statistics, and from this drawing the conclusion that the overall harm to our society's health is greater from sodas than from smoking. I am willing to accept that this may indeed be true. But the articles all appear to be making a much different claim, that:

On an individual basis, or perhaps on a per-serving basis, drinking a soda is more harmful than smoking a cigarette.

Is there any validity in this claim?

Considering that the types of harm inflicted by each substance is different, I'm open to suggestions on how to best compare the two. Two proxies I can imagine for comparing the two might be:

1. Given a habitual smoker who smokes N cigarettes per day, compared to a soda drinker who also consumes N fizzy drinks per day, who is likely to have the higher medical bills from chronic disease?

2. Drinking N sodas reduces a person's life expectancy by an amount equal or greater than the smoking of N cigarettes.