I have to write an essay on the lack of proper nutrition.

This is my introduction paragraph so far:
The Lack of Proper Nutrition

Roughly three-fourths of the world’s population has an eating lifestyle that is very low in vegetables, fruits, dairy, and oils (“Chapter 2 Shifts Needed,” n.d, para. 1). These foods are very important and they are required to create nutrients in the human body to be able to function on a daily basis.

I am needing to include my thesis statement. What would be a good thesis statement for the lack of proper nutrition?

I think I understand, thank you!

I think I found my argument: Good nutrition is more important than exercise.

https://www.powa.org/convince/stating-your-proposition.html

1. Read carefully. Very carefully. Then read it again.
2. Scrap what you wrote above (or at least put it out of sight, far away). How can you write an introduction to a paper you haven't written yet?
3. Read, re-read, and follow directions here: https://www.powa.org/convince.html

In an argumentative paper, your thesis/proposition needs to be arguable. If you write something everyone already agrees with, it's not an argument! You must take a stand about your topic and then prove that you're right and your opponents are wrong.

So far, what you wrote seems like a research paper, no opinion or argument involved.

Ahhhhh! Good one!!

First paragraph is written..

Having good nutritional habits will have a greater impact on your body both physically and mentally. Nutrition can affect how someone feels, looks, acts, and even how alert someone is. Physically, bad nutrition can cause someone to have a lower body strength compared to someone who has great nutrition habits. Someone can go to the gym four times a week for two hours every day doing a hardcore cardio workout, sweat a lot, even run to the point where their legs feel like gelatin the next day, however, lacking proper nutrition including vegetables, fruits, dairy, oil, vitamins, and minerals, that person will not see very much improvement on their body strength and overall physical health. This person will not shed any pounds if that is their goal. This can be compared to swimming upstream against a heavy current, they will not get anywhere physically without a healthy diet.

What do you think? Good so far?

It's very good -- clearly a rough draft, but the content is good! Keep going!!

for an argumentative essay you need to have an opposition, what is yours?

And don't miss this, either:

https://www.powa.org/convince/form-tradition-and-innovation.html