“But what about hamburgers? Hot dogs? Potato chips? French fries?”

That’s basically what my buddy was asking me, and the simple question made me feel like a simpleton. For not only did I have no response, but it also seemingly shipwrecked a pet theory of mine.

That something I thought could reduce the incidence of obesity in the United States by appeasing appetite might whet it instead.

What you’ll read next, however, won’t exactly right the ship. Just patch it up enough to keep it afloat — and smooth some of the dietary waters you need to sail.

The Hindus have long believed eating hand-to-mouth puts you in sync with the Five Elements of Nature, and I’ve long believed direct contact with food makes you more mindful of your body’s satiety cues and keeps you from overeating. I only tried intentionally doing so, though, a few years ago after I read about another one of its advantages.

That the touching of food activates the parasympathetic nervous system, which increases salivation, releases digestive enzymes, and relaxes the intestines, all of which lead to better nutrient absorption. I had been having some intestinal discomfort, you see, and felt the supersized suppertime salads I eat seven days a week were the source; hence, the following experiment.

To eat at least some and sometimes all of it not with a three-pronged fork but a five-fingered hand. Although it wasn’t much of an experiment, it was a successful one, so the practice is now a habit.

I’ll grab a bit of red leaf, green leaf, or spinach; wrap it around a slice of tomato, mushroom, pepper, or pickle; and pop it in my mouth. There’s little mess since I haven’t used any sort of salad dressing for years.

Five nights a week, I’ll snack on salad this way as I prepare the omelet or shirataki noodle, fat-free mozzarella mix that’s part of that supper. I’ll eat the entirety that way the other two nights while I wait for potatoes to bake.

Now I’m telling you all this because it’s what I told my buddy during an easy stretch of a not-so-easy bike ride. When I shared that aforementioned pet theory of mine — that if more people would give up the fork and eat hand-to-mouth, fewer people would be fat — he said something like, “So what about burgers and fries? People hold them and people still overeat them.”

While I didn’t know how to respond then, I do now. It’s based on what cellular physiology researchers have recently learned about pro-opiomelanocortin neurons.

Yes, yes, a thousand times yes, pro-opiomelanocortin neurons is a god-awful, off-putting term. And yes, again, there’s no good reason for you to already know anything at all, unless you’re a physiologist, about what we’ll now call POMC neurons.

But knowing a bit about exactly what POMC neurons do can help you, for even physiologists fall into one of the three following categories: the nearly 42 percent of American adults who are obese, the nearly 31 percent who are overweight, or the rest who’d rather not join their ranks.

In a study published in late May in Nature Metabolism, cellular physiology researchers teased mice by placing food protected by wire mesh in their cages. So they couldn’t eat it, but they could see it and smell it, which activated their POMC neurons and triggered the same metabolic response that occurs when you eat.

Namely, blood sugar rises and insulin is then secreted.

Now there’s far more to this study, but what’s most important for you is what the Yale School of Medicine press release highlights. That the research clearly shows the POMC neurons are activated not only while eating, but also with the anticipation of food.

In that same presser Marc Schneeberger Pane, PhD, assistant professor in cellular and molecular physiology and the study’s co-principal investigator, calls obesity “a dysregulation of the feeding circuitry” and “more a disease of the brain than the body.” Which brings us back to my still-floating theory, albeit with some water in its bilge.

Central to it is the notion that eating hand-to-mouth helps regulate “the feeding circuitry” and therefore lessens obesity. Since many of the fast foods and ultraprocessed snacks implicated in the obesity epidemic are eaten that way, however, there’s good reason to believe what my buddy insinuated: that hand-to-mouth eating is actually a cause of obesity.

But there’s an even better reason to believe what sort of food goes from hand to mouth is the real issue here.

For the Yale study also explains how seeing and smelling food makes you hungry, which isn’t necessarily a bad thing if you’re in the kitchen cooking.

But it can be a very bad thing if you’re at the convenience store to pick up a dozen eggs or a gallon of milk — and you see all the unhealthy snacks and smell all the fast food on the grill.