evidence: - It is a high starch or high carbohydrate food. So, in the end, yes, oats can spike your blood sugar, putting you on a "sugar-high" your body doesn’t necessarily agree with. This could potentially cause excess weight gain. [...] So, back to the original question… is oatmeal healthy? I think it is fair to say that the pros of oatmeal still outweigh the cons. Although it is important to note the cons given that oats are not an end all be all. The most important factor is listening to your body. How does it respond to a bowl of oats? [...] But the secret to making oats healthy is not eating them alone or with a heaping mound of sugar.