There's one simple way to pick the healthiest nut butter

A fiery debate is raging in the world of sandwich spreads: Which nut butter is the healthiest?

Gone are the days when peanut butter reigned supreme as the spread of ultimate convenience. 'It has protein! It's smooth (or crunchy)! It's delicious!' people once cried.

New nuts (and seeds!) have entered center stage in recent months. From almond to cashew, walnut to sunflower, the dozens of options can seem staggering.

But according to registered dietitian and nutritionist Andy Bellatti, there's a super simple way to ensure your nut butter is a healthy option: Make sure it has only two ingredients.

"If the only ingredients are nuts and salt, just natural nut butter, that totally works," Bellatti told Business Insider. "It can be peanut butter, which P.S. is around four times cheaper than almond butter. It's still going to have your protein, healthy fats, and vitamin E."

You can get a 16-ounce container of Smucker's Chunky Peanut Butter (ingredients: peanuts and salt) for $2.94 at Walmart; a 16-ounce jar of California Almond Butter (ingredients: dry roasted almonds) costs $12.99, by comparison.

Still, no one should be going on an all-nut-butter diet. These spreads are high in fat and, while they do pack some protein and essential vitamins, they're pretty calorie-dense. Two tablespoons of Smucker's packs 210 calories and 16 grams of fat; the same serving of the California Almond Butter has 170 calories and 15 grams of fat.

If you're looking to pack an alternative lunch that saves time, try a turkey breast sandwich on whole wheat with a couple slices of avocado or some hummus. The white meat is high in protein and low in fat and calories, while the avocado and whole wheat bread pack some healthy vegetable fats and fiber to keep you feeling satisfied.

While almost frustratingly straightforward, this advice hints at a bigger problem in the food industry, which is the fact that food trends can often supersede solid nutritional advice, says Bellatti, who works as a health coach.

"A lot of the people I coach say they want to lose weight, but everyone goes looking for the magic bullet. When there's something new, like almond butter, they think 'Oh, here's what I've been missing all these years!'"

But it's rarely that simple.

Instead of going after the latest health fad, there are a handful of principles based on scientific studies and research that you can stick to. In general, says Bellatti, try to avoid things like powders, pills, and anything that claims to provide benefits in really vague terms. "If something says it can 'harmonize your aura,' that's a red flag," says Bellatti. And talk to the people around you for inspiration.

"I tell people to look at their friends and family members who are living the type of life they want to live," says Bellatti. "Look at these people and say, 'What are they doing?' Oftentimes, the people in your life who are the healthiest are probably doing really practical things, like avoiding soda and fast food, getting enough fiber, and eating more whole foods and less junk."