Perhaps there shouldn't be, but I suspect there will be at least a subconscious linkage in the minds of many in the Conservative ranks to the forthcoming vote on gay marriage (pencilled in for 5 February, I gather) where it looks as if Cameroon loyalists and Lib Dems (and most Labour MPs) will be pitted against a very large number of Tory backbenchers.
The person who isn't overweight also should be aware of his or her own insecurities and possibly a subconscious need to sabotage the partner's weight-loss efforts.