And, every bite makes a difference.
"The gut influences very heavily the whole body's physiology," said Dr. Hariom Yadav with the USF Center for Microbiome Research.
And now, new research shows many people may be increasing their risk of dementia because of what they put on their plate.
The main culprit: ultra-processed foods, like fast foods, chips, frozen meals and sodas.
Researchers in Brazil found that those who got 20% or more of their daily calorie intake from processed foods had a 28% faster rate of cognitive decline than those who ate less processed foods. That means in a standard diet of 2,000 calories a day, 400 calories worth of processed foods can cause a lot of damage.
But there's good news as well.
"If you eat the right diet, you can reduce that risk", said Yadav.
And, if you want to continue to eat yummy processed foods, you can still eat a lot of unprocessed foods such as fruits, vegetables and whole grains to combat the risk associated with the processed foods.
A study from Rush University Medical Center found that those who closely followed something called the "MIND" diet for four and a half years, which focuses on eating mainly vegetables, fish, chicken and whole grains, reduced their risk for Alzheimer's by 53%.
Experts say a whopping 58% of what Americans eat comes from ultra-processed foods. Even plant-based alternatives, like plant-based meat, are likely still highly processed.
So, since it may be impossible to cut out processed food entirely, experts say it's best to focus on adding unprocessed foods instead of cutting out processed foods.