Your intro:
In the course of the last hundred years( Find the simple and short phrase) , the average weight of people in some countries has increased perceptibly. Simultaneously, the levels of health and fitness of those people have worsened significantly. In this essay( For me, this adds no value) , I am going to discuss the primary reasons of this issue and give some solutions to them.
This is good. However, some points are verbose.
Topic:
In some countries the average weight of people is increasing and their levels health and fitness is decreasing.
What do you think are the causes of these problems and what measures could be taken to solve them?
It is always better to start with:
1. I highlight the key points.
2. Then rephrase the question.
Here are they:
average weight = obesity
levels health and fitness is decreasing = lack of wide-ranging health care and fitness
the causes = the main factors
to solve them = to tackle the problems
Here you go:
A general lack of wide-ranging health care and fitness leads health problems. One example is obesity. I would argue life-changing decisions can be the main factors. I too believe the best measures can be taken to tackle the problemsTo begin with(I know this is a good phrase for an opening paragraph. However, you may omit it if you think that you want avoid overusing words) , one of the principal reasons of increasing the weight of some people is
sedentary lifestyle(should be a plural form. Write sedentary lifestyles) , which is mainly caused by the development of technology. For example, in earlier times,
the sources of amusement were not in large numbers and all of them required physical presence( I didn't catch this area. If you could, rewrite it) .