Reduce the Waistline for Health and Longevity.

Increased waistline is linked to a number of disorders, and calorie restriction has been linked to increased health and longevity. Severe calorie restriction for the purpose of extending lifespan is not advised: The benefit is probably due to a reduction of intake of food toxins (which can be negated in other ways), a reduction of insulin, or reduction of metabolism and associated oxidative processes.

Food is one of the joys of life, and to deny yourself food will surely make life FEEL longer...

Anyway, exercise and fitness is more important for reducing heart disease than simple calorie restriction. Exercise alone maintains weight loss but only at the equivalent of 60 to 90 minutes of moderate-intensity physical activity per day, because the body will compensate for exercise by reducing metabolism and physical activity during the non-exercise parts of the day. Fatness is not caused by eating fat, but weight loss requires a combination of disciplined exercise and calorie restriction, and there are some benefits to reducing carbohydrate calories preferentially.

Many foods can make you feel less hungry, so you actually eat less of other things. Coconut oil is an example. Eat slowly and relax while you eat and for a time after eating. And here's another reason not to reduce calories to the extreme - you need energy to exercise, burn fat and build muscle.