A skinny cocktail is any cocktail that is lower in calories than its original version, or a low-calorie cocktail with no full-calorie equivalent. Ideally, a skinny cocktail is below 100 calories.

Skinny cocktails have become much more prevalent in the last decade, as consumers are increasingly conscientious about what they’re putting in their bodies. Cocktails are delicious, but if you’re living that #onepeloton lifestyle, many contain enough calories to set back your morning ride. Hence the explosion of skinny drinks.

A skinny cocktail can be made one of several ways, but the core idea is replacing the drink’s sweetener with a lower-calorie substitute. Simple syrup, whether pure or flavored with things like ginger, mint, or even rosemary, is an ingredient that’s often used in many cocktails, but contains a high calorie count, since it’s made from pure sugar. An alternative to simple syrup is a lower-calorie sweetener such as agave or honey. One particularly famous drink that does this, yet doesn’t carry the “skinny” branding (but could), is the Tommy’s Margarita, as its ingredients are simply tequila, lime juice, and agave syrup. Honey is another simple syrup alternative.

Another way to make a drink skinny is by subbing out sugar-based sodas for flavored sparkling waters, or sparkling water mixed with fresh-squeezed juice. You can see this in drinks like the Skinny Paloma, where grapefruit soda is substituted with grapefruit-flavored sparkling water or a mix of fresh grapefruit juice and plain sparkling water.

There is no hard and fast rule as to what makes a drink skinny, so if you see a drink on the menu labeled as such, be sure to ask what the ingredients are if you’re really concerned about your calorie intake.