I thought this article was interesting (not a big fan of the Lose Weight Now! post-it note on the front image, though). It summarizes a study that suggests that being fit and fat is still less healthy than being thin and unfit. It basically went like this:
Overweight+Unfit < Overweight+Fit < Normal+Unfit < Normal+Fit.
They were clear that being fit while being fat is still a big positive. However, it wasn't enough to counteract most of the other health risks/problems that tend to come with being overweight (such as heart problems).
“Our findings suggest that if a patient is overweight or obese, all efforts should be made to help them get back to a healthy weight, regardless of other factors. Even if their blood pressure, blood sugar and cholesterol appear within the normal range, excess weight is still a risk factor,” said lead author Dr Camille Lassale.
So, regardless of weight it's better to be fit, but being thinner is still important to health.
There are links to the referenced studies in the article.
https://www.mnn.com/health/fitness-w...-thin-and-lazy