Is butter a carb? New York Knicks star Carmelo Anthony asked soon-to-be Cleveland Cavaliers star LeBron James, probably.

Two of the NBA’s biggest players are making headlines for their noticeably slimmer bodies after following a low-carb diet. A diet that’s contributed to James’ nearly 15-pound weight loss.

Though technically, Anthony and James are following a low-carb and high-fat ketogenic diet, which requires them to swap (most) carbs with healthy, unprocessed fats and protein. A ketogenic diet in its own right helps to promote weight loss, stabilize blood sugar, and protect against diseases, like heart disease, dementia, diabetes, and cancer.

"It was nothing short of an epiphany when I switched to a ketogenic diet," Dr. Jeff Volek, a ketosis expert and professor at Ohio State University, told Examiner. "I felt better, more satiated, and had more consistent energy."

More energy, a better performance and muscle recovery are also what Anthony and James hope to gain, Volek said. Not to mention a low-carb diet is how Los Angeles Lakers nutritionist Dr. Cate Shanahan got Dwight Howard to wean off his 24-a-day candy bar habit.

However, don’t cut carbs from your diet just yet. Some experts support a low-carb, high-fat diet and others do not. For example, Adam Bornstein, fitness writer and New York Times best-selling author, wrote an open letter to James, outlining why not all carbs are bad and don’t necessarily hurt a player’s performance.

"Carbs are not bad if they come from the right sources. They will not ruin your body or how it functions. And if you’re active, they’re downright necessary," Bornstein said, adding, "Yes, low carb diets can work. But low carbs does not mean no carbs. And when going really low (less than 100 grams) they’re oftentimes best reserved for people who are either A) inactive or B) have identified that they have a carb sensitivity."

Rania Batayneh, nutritionist and author of The One One One Diet, agrees with Bornstein when it comes to the idea of good and bad carbs. Good carbs are also known as complex carbs, and the body takes longer to break them down. Think brown rice and whole wheat pasta. Good carbs also sit lower on the glycemic index, which is a number that indicates how quick and high a person's blood sugar will rise.

On the other hand, bad carbs, or simple carbs, break down easy and are higher in sugar. These include soda, candy, white rice, bread, and pasta, as well as potatoes and all the desserts. Restricting them for so long could mean trouble down the road.

"When you remove anything [from your diet], not to mention a whole food group, you eat less calories,” Batayneh told Medical Daily in an email. “The general population turns to low-carb diets because losing the initial water leads to quicker weight loss, but [the benefits don't last] long-term. Eventually you do want a beer or piece of cake."

Eating carbs after restricting them from your diet only exacerbates their effects. When reading about the many benefits Anthony, James, and even Howard, are experiencing on their new diets, consider also their intense, pre-season training.

Like with any diet, it's best to consult with your doctor or a nutritionist before making any changes to your routine. Doing so helps to avoid nutrient deficiencies, as well as long- rather than short-term results.