Sure it's no good, but is it non-grammatical?

In an otherwise stellar take-down of the state of affairs when it comes to Big Food and our federal government, Mark Bittman writes this:

But her most public work, the 2010 document called “The Surgeon General’s Vision for a Healthy and Fit Nation,” has a decidedly mild Michelle Obama-ish tone. In discussing the obesity crisis, it lays the blame squarely at the feet of … the victims: “In addition to consuming too many calories and not getting enough physical activity, genes, metabolism, behavior, environment, and culture can also play a role in causing people to be overweight and obese.”

Put aside the imprecise, non-grammatical writing. Instead of talk about curbing the marketing of junk to children, we get a discussion of “limiting television viewing”; instead of banning soda from schools, we get “Make sure water is available throughout the school setting.” In short, instead of criticizing the industry for peddling and profiting from poison, it criticizes us for falling prey to it. [emphasis added]

That is, Mark claims to have found a sentence composed by the surgeon general to be ungrammatical. But please reread that sentence:

In addition to consuming too many calories and not getting enough physical activity, genes, metabolism, behavior, environment, and culture can also play a role in causing people to be overweight and obese.

 . . . and let me know if you find an error in the grammar of it. Specifically, here is what I see as the bones:

In addition to ___________, genes, metabolism, behavior, environment, and culture can also play a role in causing people to be overweight and obese.

If I filled in that blank with a single-word noun, such as "overeating," I bet Mark would never label it ungrammatical. The question remaining is whether the phrase used in the original sentence acts as a noun phrase that could work as a noun. Here it is:

consuming too many calories and not getting enough physical activity

This phrase acts as what is commonly called a gerund phrase. A grammar expert—a real grammar expert—would, I know, be able to tell you more specifically about how this operates in the sentence, but the basic description of "gerund phrase" is good enough for our purposes: A gerund phrase begins with an "ing" verb acting as a noun. In this case the two conjoined gerund phrases are "consuming too many calories" and "getting enough physical activity" with the second of them negated by the "not" prefixed to it.

The opening phrase works just fine as a noun, and the sentence should not, therefore, be construed to be non-grammatical. So far, so good, but let me conjecture a little more about Mark's thinking and say a word about one thing that may contribute to what people judge as bad writing.

When I first read that sentence, I messed up the "In addition to" part and started trying to read the first part of it as a modifying participle phrase. In fact, the very same phrase could be used that way in a sentence like this:

In addition to consuming too many calories and not getting enough physical activity, Jared watches too much TV and has poor dental hygiene.

And if you read the surgeon general's sentence that way, you start trying to make this phrase into a dangling modifier, as if it were "genes" that were "consuming too many calories and not getting enough physical activity." It is possible Mark is referring to that sort of problem when he calls it non-grammatical, but I think it's more likely that Mark is just using non-grammatical as an umbrella term for "bad writing," and this sentence surely is an example of that.

To make this a better sentence, the confusion created by the opening phrase needs to be eliminated. There is more than one way to do that; here is just one possibility:

Consuming too many calories and not getting enough physical activity can contribute to weight problems. Other factors could be genes, metabolism, behavior, environment, and culture.

That is still not great, but it does the job of making it easier on the reader. I think it puts it more clearly into the realm of what people might call bad writing (isn't "not getting enough physical activity" synonymous with "behavior" in this context, e.g.), but those critics would not actually call it non-grammatical.

Mark's other complaint—that the information in the sentence is imprecise—has not been addressed, but if I wanted to be snarky I could shoot back: You say it's imprecise. Could you be more specific?

I wrote more on the topic of using grammar as an umbrella term for usage problems here.