You might think that any bowl of cereal is a nutritious start to your kid’s day, but a new study should make you change your tune. Data released today by the Environmental Working Group (EWG) found that some cereals are so sweet, they’re more like dessert. The EWG’s rankings are based on percent of sugar in the cereals by weight, and the results are pretty staggering.

The sugariest culprit of them all is Kellogg’s Honey Smacks, which packs 15 grams of sugar per 3/4-cup serving. That’s the equivalent of 3.75 teaspoons — more than half of what the American Heart Association recommends kids eat for an entire day. In this case, it’s not only what’s in the cereal that’s the problem, but also what’s not there: Honey Smacks have only 1 gram of fiber and 2 grams of protein — not a very filling start to your child’s day.

To round out the top 10, here are the EWG’s other worst kid’s cereals, listed by percent sugar by weight.

1. Kellogg’s Honey Smacks — 55.6 percent
2. Post Golden Crisp — 51.9 percent
3. Kellogg’s Froot Loops Marshmallow — 48.3 percent
4. Quaker Oats Cap’n Crunch’s OOPS! All Berries — 46.9 percent
5. Quaker Oats Cap’n Crunch Original — 44.4 percent
6. Quaker Oats Oh!s — 44.4 percent
7. Kellogg’s Smorz — 43.3 percent
8. Kellogg’s Apple Jacks — 42.9 percent
9. Quaker Oats Cap’n Crunch’s Crunch Berries — 42.3 percent
10. Kellogg’s Froot Loops Original — 41.4 percent