This is the 15024th most frequent Russian word.
подчеркивают
"Подчеркивают" means "emphasize" or "stress."
In this sentence, 'подчеркивают' is used to indicate that studies are emphasizing or highlighting the significance of something, in this case, healthy eating.
Исследования подчеркивают важность здорового питания.
Studies emphasize the importance of healthy eating.
Here, 'подчеркивают' is used to convey that the colors serve to bring out or draw attention to the mood of the painting.
Цвета на картине подчеркивают ее настроение.
The colors in the painting accentuate its mood.
In this instance, 'подчеркивают' means that the authors are stressing or underscoring the importance of continued research.