why do some people gain excessive weight and some do not?

Question

is it because of age,living style,or metablism

Answer 1

That's a very simple but also complex issue. And you point out all the critical factors. It essentially boils down to a basic formula of calories ingested versus calories expended. But the variables, such as those you mention, all influence the end result of the formula.

Age - Unfortunately, age often brings several health complications (regardless of how healthy you are) and these often influence metabolism. The older you become, the slower your metabolism, greater loss of muscle and overall decrease in physiological efficiency to burn calories at rest. It's also much harder to exercise at moderate or intense levels as it is to recuperate quickly. But you're never too old to exercise and for some people, their "real age" is often much younger (or older) than they think, and this has an incredible influence on metabolism.
http://www.preventdisease.com/healthtools/articles/health_age.html
http://preventdisease.com/fitness/fitadults/articles/your_never__too_old.html
http://preventdisease.com/home/weeklywellness210.shtml


Metabolism - Probably the single most factor in the determination of calories utilized for energy. The higher your Basal Metabolic Rate (BMR) is, the more productive you are at burning calories at rest. Whether it be through genetic predispostion or lifestyle adaptation, those with higher metabolisms can always utilize calories for energy better than those with lower metabolisms. Geographic location, environmental temp, body-type, diet, body composition, supplementation and some genetic factors all influence metabolism.
http://www.preventdisease.com/healthtools/articles/bmr.html

Lifestyle - The way you live, eat, stay active and your mental state, are the most significant factors affecting your metabolism. People who are sedentary have little chance of maintaining or increasing their metabolism as they age and consequently most gain weight. People who make the wrong food/beverage choices (consistently) on a daily basis set themselves up for improper digestion and elevated blood glucose with diets full of of sugar, saturated fats and unproductive calories which influence everything from their bodies to their mental state. If you travel around the world, it is truly amazing how lifestyle influences health and weight gain and how evident this is in different parts of the world. This is painfully obvious in non-Western cultures. Nutrition and exercise are part of lifestyle but deserve their own categories.
http://preventdisease.com/news/articles/040805_mediterranean_diet.shtml
http://preventdisease.com/news/articles/112505_mediterranean_diet.shtml

Nutrition - You are what you eat. This is so true in every sense. Eat crap and you'll feel like crap. Eat well, incorporating wholesome and nutritious foods in your diet and you will reap the benefits, keeping your weight down and have lasting energy levels. Again, western diets are full of simple carboyhydrates, sugars, saturated fats, processed and unhealthful calories which are not conducive to good health or productive for weight loss or weight management. If you observe people at the grocery store, their body-types often reflect what's in their grocery carriage. It's hard to always eat well as there are so many delicious, sinful foods to feast on. But the difference between the healthy individuals who are able to maintain their weight, and the unhealthy individuals who have excessive weight, is daily food choices which greatly impact their long-term health. Meals filled with vegetables, fruits, complex carbohydrates (such as brown rice, oatmeal), and high-quality protein such as lean beef/chicken/fish should be a staple in your daily diet for weight management. Yet, the majority of Americans don't consume nearly enough of these as they could or should. Grocery foods are not what they used to be either. The necessities of mass food production has created a plethora of food empires who's only goal is too produce as much food as possible with minimal cost which has had a dramatic impact on the nutrition of the food itself. Many vegetables are no longer grown in soil but water leaving them very low in vitamins and minerals. Fish is so infested with mercury that it's advisable to refrain from daily consumption http://www.preventdisease.com/healthtools/articles/mercury.html. And meats are so full of hormones that we have yet to see what they will do to our long-term health with repetitive consumption. This too has degraded our health.
http://www.preventdisease.com/fitness/nutrition/nutrition.html

Exercise - At the end of our formula is calories expended. If you don't exercise or increase your Active Metabolic Rate (AMR), on a daily basis, you have little chance of maintaining cardiovascular efficiency and preventing muscle loss, two things which are paramount in determining long-term health. Exercise is critical for sustaining longevity, preventing disease and weight management. Fitness means different things to different people, but the fact remains that any exercise is good. Our bodies have evolved to be active and constantly moving, NOT sedentary. If you want to prevent heart disease, diabetes, osteoporosis, cancer (yes cancer), obesity, then exercise should not only be recommended but an essential part of life. Those who think they have no time for exercise will soon have to make time for illness.
http://www.preventdisease.com/prevention/physical_activity_fundamental.shtml
http://www.preventdisease.com/prevention/exerprevent.html

So there you have it in a nutshell. You can probably branch off into a dozen other directions and incorporate several other variables, but the basics are above and the causes inherently clear.
.
.

Answer 2

mainly a combination of all 3. For instance, i have a friend, (he's 19) who eats a ton of candy and other food with pretty low nutritional values, as well as not working out. somehow, he only weighs about 120 (he's about 5'10") and has very little fat on his body. That would be attributed to his metabolism. of course, as you age, metabolism slows, but if you lead an active lifestyle, you can help counter that.

Answer 3

Sweet potatoes help you lose weight

Answer 4

mostly it is imbalanced diet & living style ( less physical activity )are the main causes for gaining unwanted weight.

Answer 5

check the following webpage, a good article about - 'can eating certain foods help you lose weight'.

http://artcademy.bacarra.biz./Can%20Eating%20Certain%20Foods%20Help%20You%20to%20Lose%20Weight.htm

Answer 6

All of the above plus heredity.

Answer 7

all of the above

Answer 8

all of those reasons.