Statistics Canada reports that 23.1% of Canadians are obese and 36.1% are overweight based on Body Mass Index (BMI). BMI can be easily calculated by taking your weight in kilograms and dividing it by your height in metres squared. BMI can inaccurately label atheltes with lots of muscle as overweight but for most of use it is useful measurment. BMI of 30+ means you are obese and 25-29.9 puts you in the overweight category.
There are hundreds of diet books, plans, programs and strategies.