Then it says "Anything that gets children moving is a step in the right direction, however...".
That's a contradiction. You can't have it both ways. Either there's evidence that PE classes help or there isn't. You can't say research shows that PE has no effect on weight but PE classes will help anyway.
If you read a lot of news about various studies you'll see that it's a common error. When people really want to believe that X works they have a hard time accepting evidence to the contrary. You will find statements such as "There's no evidence that X helps Y but based on our theories/logic, we believe X should help Y so we should keep doing X".
The other common response is "The evidence shows no link between X and Y but that just means we need even more X". In other words, "My belief that X works is still correct, we can ignore the data because we was wrong about how X we needed".
That response also shows up in the article linked: "..researchers said that PE classes were falling short and suggested a curriculum where children get more activity than classes currently offer".