January is looming, and we all know what that means: A resolution to lose weight and get healthy. Just like the 2015 declaration. And the one before that.

What diet to choose this time? Low-fat? Low-carb? Gluten-free or prehistoric? Or just throw out the scale and surrender to fate and French fries?

Stop, take a breath and consider instead a seven-word alternative offered by prominent food writer Michael Pollan that embraces clarity and shuns extremism.

Here goes: Eat food, not too much, mostly plants.

Behind that advice is a wealth of scientific, medical and anecdotal evidence as explored in the documentary “In Defense of Food,” airing 9-11 p.m. EST Wednesday on PBS stations (check local listings).

Pollan is an amiable, engaging guide through a buffet line that includes the how and why of the modern diet, the ever-shifting barrage of confusing, conflicting decrees (Don’t eat eggs! Eat eggs!) and, most importantly, realistic alternatives to chew over.

“The more I worked on this issue, the more I realized that painting things in black and white is not the way to help people move, because people move incrementally,” said Pollan, whose books include In Defense of Food: An Eater’s Manifesto and The Omnivore’s Dilemma.

“Relaxing about our eating is really important, too. I don’t want to make people more anxious about it,” he added. “We already are made very anxious.”

But there is reason for concern. A sharp rise in U.S. obesity and diabetes parallels our devotion to a diet heavy in meat, white flour and fat.

And sugar: We consume about 1,000 percent more of it per day than we did 200 years ago, Dr. Robert Lustig , a professor at the University of California, San Francisco, says in “In Defense of Food.”

Among the guidelines Pollan offers in the documentary:

“When I say, ‘Eat food,’ I’m basically saying eat the kinds of things that people have been eating for a long time,” including meat, fish, vegetables, fruit and grains, but everything in moderation.

Avoid supermarket center aisles that harbor the processed foods that Pollan labels “edible food-like substances” that don’t deserve to be called food. “If it came from a plant, eat it. If it was made in a plant, don’t,” he says.

Use smaller plates and glasses to reduce portions.

Pollan says his inclusion of meat – in limited quantities – hasn’t made his approach popular with carnivores who feel he’s dissing their choices or with vegetarians. But it reflects his approach to being a happy and healthy eater.

“Absolutism in the quest for food is a huge mistake,” he said.

Even those eager to change their diet face daunting challenges. Processed foods are convenient, loaded with the salt, fat and sugar that “really push our evolutionary buttons” and are backed by multibillion-dollar marketing efforts, Pollan said.

And there are communities where residents have limited or no access to affordable and nourishing food (although the correlation between bad eating and such “food deserts” is more complicated than has been discussed, Pollan contends).

Whatever the obstacles, he refuses to give Americans a pass when it comes to making better choices.

Start by dropping misguided ideas and self-imposed restrictions, Pollan said. Food doesn’t have to be local or even fresh to make the grade, with frozen and canned vegetables good nutritional choices. And try cooking instead of bringing home dinner in a fast-food box, even if it’s just once a week to start.

Homemade meals can be economical as well as healthy, he said. They do take time and planning, but Pollan urges us to consider the payoff in our well-being.

“Part of my argument is this is so important it’s worth making a priority. When the (food) industry represents such an easy alternative, it’s very attractive. But you can’t let them set the agenda for you,” he said.