Should I tell hubby his weight gain puts me off having sex?

I’ve always kept an eye on my weight and have managed to stay in reasonable shape, despite having had three children. Though I still love him, I find his weight very unattractive and often look for excuses not to have sex. I don’t want to hurt his feelings by telling him the truth.
Both men and women can respond to their partner’s overweight by withdrawing their sexual interest and desire to be sexual. Is it only the weight that is the problem? There may be other changes in the relationship that have created distance.