I have been told to exercise to lose weight. Is jogging the best form of exercise?
No. The most effective forms of exercise, that work all the major muscle groups with minimal risk of stress injury, are swimming, gymnastics and cycling.
Swimming is without doubt the ideal exercise, as there is no stress on the support structures of the body, while every muscle is being worked. Group activities such as gymnastics (or variations of this such as aerobics) tend to give more encouragement to exercise, and are less boring than endlessly pacing around a grass oval by yourself. Cycling does not cause foot and leg stress, and the scenery changes rather more rapidly than in jogging.
Any form of exercise is better than none in an attempt to lose weight, but jogging has several disadvantages. It tends to cause leg and foot injuries, particularly if running on a hard surface; there are dangers in jogging on roads; and only the lower half of the body receives adequate work. Those who do like jogging should ensure that it is done on a grass surface in good quality shoes, and where there are no traffic hazards.

I am a thirteen year old girl, 164 cm tall and weigh 55 kg. I feel fat because I have fat legs. Am I overweight? What is the average weight for a girl my age?
The average weight for someone of your age and height is 47 to 51 kg, so you are a little overweight statistically. It would be equally important for me to know your degree of maturity.
Girls at thirteen can still be flat chested and have no sign of changing into a woman, or they may be well developed and appear to be a grown woman. Those with a woman’s figure will weigh more than those who are still girls.
Almost certainly you will grow taller in the next year, so the sensible thing to do is to watch your diet, get some exercise and make sure that you do not put on any more weight, and let your height slowly increase. You will grow up into your present weight, and thin out as a result. Losing weight is NOT a good idea at your age unless you are grossly obese.

Is there a simple and cheap way to lose weight?
A There are no easy ways to lose weight, only hard ones, but losing weight can be simple and cheap. There is no need to buy costly diet foods or attend expensive courses. Following these five points, while using a lot of willpower, and I guarantee you will lose weight.
1. Eat Only Three Times A Day.
Never eat between meals, and drink only water or black tea/coffee if thirsty. Set aside three half-hour periods a day for eating, and do not eat at any other time.
2. Eat Only The Correct Foods.
There are scores of diet charts available that will tell you which foods are low in calories. Do not stick to only one food group, but eat a balanced diet.
3. Exercise Regularly.
Get up a good sweat and make your heart race at least once a day.
4. Eat Less.
If you are not losing weight at the rate of four kilograms (nine pounds) a month, you are still eating too much. Do not weigh yourself more than once a week, and remember that weight loss does not occur steadily, but with sudden weight loss, and then a period of no loss. That is why the loss must be averaged over a month.
5. Keep Going.
It is pointless spending months losing weight, only to put it on again. Your diet should be one for life, not just a few weeks or months.

What causes obesity? I am very careful with my diet, but still overweight.
Your choice of parents is the most important factor in your weight, particularly if you do stick to a good diet. Obesity is hereditary, and children of fat parents should be carefully watched to make sure they do not put on too much weight in childhood.
The other big factor (pardon the pun!) is of course your diet. Many fat people claim they eat nothing, but when monitored they are seen to nibble little bits of food all the time between meals. Their meals may be small, but their calorie intake is enormous. Exercise is the third factor, and obviously people who exercise regularly are going to burn off more calories and fat than those who lead a sedentary lifestyle.
There are some diseases, such as an under active thyroid gland, which may be responsible for obesity, but less than 1 in 100 fat people have these diseases, and they can be easily tested for by your GP.