I didn't say the study mentioned it, I said that dietary patterns can change due to exercise. The link didn't say what they ate or didn't to maintain their weight, and I can imagine that increasing your total calories consumed can't be completely safe even if it is just for weight maintenance. That is why researchers need to control for changes in diet, changes in overall health unrelated to exercise (people do get diseases for various reasons, as I can imagine would be common to a group of previously sedentary participants), etc., to make sure adverse health changes are directly caused by exercise itself.

Of course, without a link to the papers themselves, it is hard to say how properly controlled the experiments were.

If these variables weren't properly accounted for, then overall the data should give cause to concern, but is still inconclusive.