The effects of obesity in cats

[Catherine]

When cats of normal weight were allowed to over eat they gained weight. Their digestive systems started working less well.
It is not just the weight that  is unhealthy for cats. The whole digestive system ios stressed by the extra pounds.

https://www.popsci.com/health/cat-overfeeding/

One more reason for not over eating, especially if you are a cat.
None of our body systems works well when it is stressed by extra pounds.