hi mam/sir,there is no evidence of 
atorvastatin causing weight gain.moreover it is used to decrease 
cholesterol thereby reducing weight.regarding 
weight loss tips,exercise combinet with diet is the most important principle.i advise my patients to cut down carbohydrates and fats to minimum and the daily calorie intake must not exceed 1800kcal/day.completely avoid refined or processed foods.the following foods are recommended
             1)high fibre foods like fruits(melons,guava,berries,apples 
                 etc),corn(avoid sweet corn),split 
                 beans,peas,raddish,carrots,broccoli,avocado.
              2)protein intake can be moderate.all veggies and egg can be 
                  taken.
              3)fish,oatmeal,whole wheat past,green soups can be taken.
most important is to exercise atleast for 30min/day for 4 to 5 days a week.heavy exertion is not advised for your age.you can go for a brisk walk daily.hope my explanation satisfies you.if any other queries,i'm ready to address.thank you.take care.bye.