There's an article in the Post today about how to tell a friend she's getting fat. Of course she knows, but maybe she's in denial about just how far gone she is. Or maybe she isn't taking responsibility and insisting it's her thyroid. In this case you can help her see the truth, ever so gently:
"A great number of overweight women and men have really sold themselves the idea that they are persecuted by Nature in that everything they eat turns to fat. Their friends have given them sympathy over this sad plight.
But the fact in case is that such fat people during the war in countries where food was not available to satisfy their appetites, rapidly lost weight. Unless there is a definite glandular disturbance, which happens only in one out of a hundred thousand cases of overweight, the fat in the body is in ratio to the food intake and there is no other way around it.
THERE ARE NO OVERWEIGHT PEOPLE IN PRISON CAMPS."
Margery Wilson, You're As Young As You Act (1951)