There is an epidemic of obesity.
The core correctives are well known. Eat less and exercise more. Simple, affordable, effective. Eating less is by far the more important. To lose weight solely by exercise is close to impossible for normal individuals.
A couple of points. In eating less keep going with fruit and vegetables and leave off the big starchy foods - bread, potatoes, rice, pasta etc and of course the sugary drinks.
In exercising more, stick to walking - anything else will bring its own problems. Walking more will have most effect in a hilly environment and in colder climes.