Obesity
In 2014 Sultan Qaboos University published research showing that 30% of the Omani population was overweight and 20% was obese.
Smoking
A ban on smoking in public places was introduced in 2010. Restaurants, malls and other public places were required to allot more than 50% of their space as non-smoking zones. 70% of residents suffer from some kind of curable disease related to smoking.
References
Health in Oman Wikipedia(Text) CC BY-SA