My mom has gained a little weight. This is how I plan to tell her. What do u think?

Ok, my mom's father is kind of chubby and my mom has been skinny her whole life. However since she has turned 47 in November, I've noticed she is getting a little bigger. Nothing serious, just you know, what I think could be the start of a problem? And I think she should knock it out right away before she becomes chubby like my grandfather and life becomes harder for her. I usually try to tell her how bad fatty foods are like the junk food and other stuff, but that's not working and she keeps on eating the chocolate cake my grandfather brings over. It's led her to buy it from the store. I am planning to walk up to mom this evening and say, "Now, you know I love you but if you don't want to become a hippo, STOP EATING ALL THAT CAKE AND EAT AN ORANGE FOR CHRIST SAKE. I LOVE U AND GOODBYE!!!