According to the outline below prepare an essay about 400 words?

Causes of Obesity in the 21st Century
Obesity is a major factor in a wide range of health problems. Obesity is a medical condition where excess body fat gets accumulated to such a large extent that it can have an adverse effect on a person's health.
Thesis statement:
There are numerous causes of obesity. However, the most essential causes of obesity among people of the 21st century include passive life style, unhealthy food, and Lack of awareness 
BODY ONE: 
Topic sentence ONE
The obvious and main cause of obesity is a passive life style
Supporting detail 
A: People are getting fatter because they're more sedentary, and spend hours in front of TVs and computers.

B: Advancement of technology is another factor that makes people more laziness, while such advances may have made our lives easier in the short-term, they may also be making our lives shorter as well.

C: They are more likely to gain weight because they don't burn up the calories that they take it from the food.
Concluding sentence:
People need to do some exercises

BODY TWO: 
Topic sentence TWO:
Another major leads to obesity is the unhealthy food.
Supporting detail
A: Most of people do not care about what they eat
B: Fast food and soft drinks are more accessible, while it's high in calories and fats
C: Most towns and cities have a fast food chain located on nearly every corner, and our television screens are filled with advertisements for the various restaurants and their newest selections.
Concluding sentence:
Healthy food plays an important role to prevent people from being obese.


BODY THREE:
Topic sentence THREE:
Many people having lack of knowledge about causes of obesity

Supporting detail 
A: Most of the Parents don't instruct or teach their children the way of a healthy life.
B: some obese people have no knowledge about obesity that it can be hazardous to a person's health and quality of life as well as the root cause of several diseases
C: Governments don't help people improve their lifestyles and health conditions
Concluding sentence:
It is very important to spread awareness about healthy living in the world in order to help people improve their lifestyles and health conditions
CONCLUSION
In short, there are three main causes of obesity; passive life style, unhealthy food, and Lack of awareness. It is good to being healthy and fit than being obese. Exercise is very essential to keep the body fit. The body has to be toned up regularly. Exercise helps improve overall vitality and makes one feel energetic and vibrant, so keep your body fit and healthy. The best way to tackle this problem is by spreading awareness on the benefits of healthy living and healthy eating