These days, supermarket shelves are loaded with products claiming zero grams Trans fat per serving. But that “zero” on the label is not necessarily really zero.

In fact, it can mean almost as much as half a gram of trans fat per serving. All that bad fat can really add up.

Trans fat is really a man-made chemical that replaces natural fat. Fats are made up of hydrogen and carbons. Food producers have learned how to combine these two elements to make a product that is almost like the “real” food, but suppose to be healthier for people to eat.

The Food and Drug Administration (FDA) has rules for manufacturers and consumers. What consumers do not know is how to read labels. According to the FDA guidelines, products only need to have less than 0.5 grams of trans fat per serving to claim zero grams trans fat.

But even that is still too much. Just one of these so-called “zero grams trans fat” servings at each meal could add up to almost 1.5 grams trans fat per day over breakfast, lunch, and dinner — and that is not including snacks.

Imagine: that is almost 75 percent of the American Heart Association’s recommended daily limit of 2 grams (about 1 percent of your daily calories, based on an average 2,000-calories diet) and could total almost 547.5 grams trans fat each year! The number of trans fat is a whole lot more than zero.

So what does this mean for consumers?

As is often the case, the consumer must be aware of serving sizes. Along with that please know that at times it is best to eat more natural fats rather than man-made fats. Always check with your doctor about recommendations.

Look for words on labels like “partially hydrogenated” or “shortening.” Just be aware of what you are putting into your body.

That is the lesson you as a consumer are in charge of for the rest of your life.