By Sara Rennekamp, Inside Science  -- News broke this week that the company behind the popular Kind line of snack bars received a warning letter from the Food and Drug Administration.

Their offense? Not labeling the bars according to FDA rules -- primarily due to slapping a "healthy" label on a product that did not meet the FDA standards for healthy.

The FDA has strict parameters for how some foods are labeled and marketed to consumers. Any food that uses the word a "healthy" or "healthful" in its marketing -- really any implication that the food you're about to consume will somehow enhance your health -- better measure up to what the FDA considers "healthy."

The charges

In this case, the Kind bars in question – Kind Fruit&Nut Almond&Apricot, Kind Fruit & Nut Almond & Coconut, Kind Plus Peanut Butter Dark Chocolate + Protein, and Kind Fruit & Nut Dark Chocolate Cherry Cashew + Antioxidants – all exceed the amount of saturated fat per serving necessary to merit the "healthy" label.

These bars also don the phrase "Good Source of Fiber," and by most standards, they are. However, the FDA requires that if a food is to be labeled and lauded for its fiber content, it must also contain less than 3 grams of total fat per 40 grams of food, or clearly indicate that while the food is high in fiber it is not low fat.

The Kind bars in question make no mention of fat other than what is listed in the Nutrition Facts even though each bar has at least 9 grams of fat per 40 grams of food, and most of them have more.

There were also questions about the company's touting of the bars' levels of antioxidants and fatty acids, and how they dealt with labeling rules for trans-fats. Finally, Kind failed to "accurately declare the place of business as required by 21 CFR 101.5(d)," according to the letter, by failing to list a street address on the bars' labels, opting for a P.O. Box instead.

Shame on you, Kind!

Of nuts and fats

The reason the saturated and total fat content is so high in the offending Kind bars is probably because they contain a lot of nuts. Nuts are high in many good things: protein, fiber, potassium; they're also notoriously high in fat.

The body of nutrition research is constantly changing. It wasn't that long ago that masses of people were recommended or put themselves on a diet very low in fat. Fat, according to the prevailing research of the time, was the enemy of health.

But research on fats since then has made important distinctions between the different types of fat found in food. For example, the fat you'd consume if you ate a tablespoon of butter is very different than the fat you'd consume eating an avocado or a few almonds. Your body also processes and uses those fats in different ways. The Mayo Clinic has a primer on dietary fats that is helpful in distinguishing "good fats" from "bad fats."

Nowadays, there's a new appreciation of fat (especially the "good fats"). Studies delineating the different kinds of fats and their possible health benefits are more plentiful. High-protein diets – which usually also mean high-fat diets – are all the rage (think: Atkins and Paleo), and fat enjoyed a cover story in Time Magazine last summer.

Fat is back on top.

Even saturated fat, the main offender in the sanction of Kind Bars, is experiencing a comeback. Time Magazine's June 2014 cover story not only touted the merits of fat, but admitted mea culpa for their previous involvement in the "War on Fat" of the 1980s and 1990s.

Why so serious, FDA?

With all the research touting the merits of fats – especially from nuts – what's the FDA's problem with Kind Bars? I think part of the issue is that the government is a relatively slow-moving train when it comes to changing its standards. This usually isn't without reason. Nutrition science is constantly evolving and it's a challenge for even physicians and dieticians to keep up with the changing research and subsequent trends.

There's also the question of accurate marketing. At the end of the day, Kind is in the business of selling a product and foods that are marketed and perceived as healthy certainly sell. Just look at the boon in sales the organic label has enjoyed for the last several years. Some health food companies will go so far as to make claims about their products that are completely unsupported by any sound science.

For example, POM Wonderful Pomegranate Juice received a similar letter from the FDA in 2010 for using unsubstantiated health claims to sell their line of juices. Coca-Cola was sued by the FDA for their line of Vitaminwaters that made certain unsubstantiated health claims. Last year, the Daily Beast ran a scathing article about the health claims made by various companies whose products are sold at Whole Foods. Similar products are also available at smaller, less well known health food stores, not just Whole Foods.

It's difficult to know if Kind's offenses are as grievous as those of POM and Coca-Cola. What is clear is that health food marketing is powerful and persuasive.

Ignore the front, read the back

Marketers are going to do what they do and this certainly will not be the last time a food company runs afoul with the FDA. At the end of the day, though, most of us just want to make sure the food we eat is reasonably safe and healthy. What's a consumer to do?

The answer is simple, boring and you've probably heard it before: read the Nutrition Facts. The front of food packaging is designed to convince you to buy that food. The Nutrition Facts list the boring, naked truth of what the package actually contains.

Sara Rennekamp is News Editor for Inside Science. She tweets at @SaraRoseHalley and often daydreams about black holes.Reprinted with permission from Inside Science, an editorially independent news product of the American Institute of Physics, a nonprofit organization dedicated to advancing, promoting and serving the physical sciences.