Do you have enough sleep every night? Otherwise, you will become obese. It is suggested that a lack of sleep is relevant to the risk of obesity, according to some studies.
However, it is not always applicable in any environment. Especially, the relationship between sleeping time of children and the rate of obesity is somehow skeptical.
The Conversation: Does a lack of sleep really make children overweight? Here’s the science
In this article above, the fact that sleeping time in children has been shortened in many countries through this century, whereas it is the opposite in the UK and Australia. Also, some studies suggesting the causal relationship between less sleep and weight gain in children are doubtful of their clinical validity, according to the author. For example, the difference of sleeping time in the two groups of children classified by the body weight shown in a study was only 14 minutes. This finding obviously does not make sense, even though there is statistical significance in it.
I am not familiar with children' health. But I guess dietary habits and frequency of exercise, as well as genetic factors, have more impact on their body weight than sleep.
However, it does not mean keeping good sleep is meaningless in children. It has been proven that growth hormone is secreted while children are sleeping. As well, some other hormone levels are modified in the midnight. Disturbed sleep is easy to bring children malfunction both physically and mentally. Even if it does not prevent obesity, deep and enough sleep is crucial for children.