Estimations about the number of men with habitual snoring show marked differences. One Swedish study made a questionnaire with males and found a prevalence of 15% among the male population. After 10 years 20.4 % of the same population were habitual snorers.
The most relevant risk factor was the Body Mass Index (BMI). Obese men have a much higher risk of snoring. This is well known to nearly all doctors, so they will recommend weight reduction to reduce snoring. Thus, additional weight gain seems to be of special relevance.
Persistent smoking was another possible marker for severe snoring. So maybe the reduction of cigarrettes (or an attempt to stop smoking) would be a good choice!
The number of snorers increased until the age of 50 to 60 and then decreased. So there is some hope for their wives....