There's a sweet spot of physical activity which optimizes energy expenditure:appetite. Too little or too much and your appetite is higher than your expenditure.
https://www.ncbi.nlm.nih.gov/pubmed/22855277?dopt=AbstractPl...
https://www.ncbi.nlm.nih.gov/pubmed/22855277?dopt=AbstractPl...
The article seems to say that the 60-min cardio group had been closer to that sweet spot, but it's not very concrete about that assumption.