It’s creamy. It’s healthy. In fact, recent research from Harvard University identifies yoghurt as one of the best foods for weight loss—think low GI, high protein and a bone-strengthening boost of calcium. But not all varieties are health heroes. Here are five sneaky saboteurs to avoid:

The sugar bomb

There’s fruit and then there’s ‘fruit’. Many yoghurts with pureed, sweetened fruit mixed in are loaded with more sugar than a chocolate bar. Plain yoghurt a bit tart for your taste? Mix in a teaspoon of honey, add banana slices for energy, walnuts for omega-3 or blueberries for an instant dose of antioxidants.

The fat trap

Greek yoghurt may be thick, creamy and delicious, but it’s also high in fat. “It generally contains 8-10% fat compared with 4% for normal yoghurt,” explains nutritionist Catherine Saxelby. The simple solution? Low-fat Greek yoghurt is just as rich in calcium and protein, with less than 3% fat. Win-win!

The smoothie

The yoghurt smoothies found in juice bars across the country are often no different to a milkshake in disguise: some have as many kilojoules as a bowl of ice-cream. So how can you make sure you get all the benefits without the sugar? Mix your own with unsweetened frozen berries, plain yoghurt and low-fat milk.

Dessert in disguise

If it sounds too good to be good for you, then it probably is. “Dessert yoghurts may contain a little bit of yoghurt, but there’s also added cream or chocolate, and flavouring like cheesecake, caramel or tiramisu,” explains Saxelby. “These are really an indulgent dessert, rather than a healthy snack.”

What about frozen yoghurt?

Frozen yoghurt may seem like a healthy snack, but it’s not a substitute for the real thing. “It may be healthier than ice-cream with less sugar, fat and a low GI, but it has twice the kilojoules of low-fat yoghurt so it’s not entirely guilt-free,” Saxelby adds. Bump up the health factor with frozen yoghurt that has live probiotic cultures and enjoy occasionally.