How to Lose Weight - diet vs exercise
As has been said many times in other articles on this site, calories count, and when the amount of energy taken in (from food and drink) is larger than the energy used (to carry out basic metabolism and physical activity), the extra energy is stored as fat in the body. So it seems clear that if you want to cut down on the amount of fat you are putting on, you either cut back on high calorie foods and drinks, or you increase your exercise / activity regime. It seems like you have two equally effective options.
Recently there has been a public debate about what is the main cause of the overweight problem that is now found world-wide. Is it diet, are we eating the wrong foods, or is it exercise, or are we just too sedentary? There is a suspicion that the food industry is behind this debate, because the conclusion that is very often reached is that a particular food or snack isn't the culprit but rather it is because after eating a particular food or snack we just aren't moving enough. So just get off the couch and go far a walk more often. You can eat whatever you want as long as you get more active.
It may be a coincidence, but we now are seeing a wide selection of wearable monitors that can measure how active you are: from cheap pedometers to expensive flashy "health" monitors. It is hoped that when you actually see how many steps you take in a day, there will be an incentive to do more the next day, and even more the day after. This has given rise to the 10,000 steps campaign. It is not clear why this number was chosen, except for the fact that it seems to be an impressive number to most people. There is a general feeling that increasing the number of steps per day is a good way to improve overall fitness. The American Heart Association, for example, uses the 10,000 steps goal as a guideline to follow for improving health and decreasing risk of heart disease. But, as a way of losing weight, adding steps to your daily regime may not be as effective as you might think.
I'm a male, 80 kg in weight, have a 50 cm stride. If I do 10,000 steps I will have burned 278 calories. If I do this for one week, I've used 1946 calories. Not bad until I get on the scale and find that my weight has hardly gone down. This is because, on average, I need to burn about 3,500 extra calories to shed one extra pound (0.45 kg), if all of those stored calories were in the form of fat, which they are not.
Being more active is part of a healthy lifestyle. If weight loss is high on your list of priorities, pushing yourself away from the dinner table before accepting that second helping of desert may be the best exercise you can do.
Diet, exercise or diet with exercise: comparing the effectiveness of treatment options for weight-loss and changes in fitness for adults
J Diabetes Metab Disord 2015,14:31