The first article discusses how junk food messes with our brain chemistry, making us stupid and not feeling full. Thus triggering a desire for more junk food.
The second article found that if you need to sit all day, kneeling or squatting is much healthier for people, than sitting on a chair.
Vocabulary and Sample Sentences:
Undermine v.: make something weaker or less effective
Amiss adj + adv.: not as it should be
Sedentary adj.: a lot of time sitting