Topping the list as one of the foods that can have the biggest impact on your health, is good ol' refined sugar. "Refined sugars include easily digestible sugars like table sugar, high fructose corn syrup, and other added sugars," Oreoluwa Ogunyemi, MD, tells Bustle. "While it's OK to have small amounts, simple sugars cause health problems in several ways."

For example, simple sugars can feed infection-causing bacteria and yeast in the body, Dr. Ogunyemi says, which can lead to bowel problems and inflammation over time. "Sugars also cause hormone imbalances that lead to high blood sugar and metabolic problems like diabetes," she says.

And finally, "elevated sugar levels cause our immune system to go into overdrive, increasing our risk of autoimmune disease as well as direct damage to our intestines, causing illnesses like leaky gut syndrome."

While the daily intake will be different for everyone, it's generally recommended that you stick to less than six teaspoons of added or refined sugar per day, in order to keep these issues at bay.

The annoying thing is, you may think you can skip refined sugar and go for artificial sweeteners instead. But these artificial sweeteners — like aspartame, sucralose, and saccharine — can have an impact on your health, too.

"Even though they have no 'sugar,' they can raise blood sugar levels leading to increase risk of diabetes," Dr. Ogunyemi says. "Infection-causing bacteria can also feed on these sweeteners causing abnormal changes in our healthy gut flora."

While they're still being researched, there's evidence to suggest that some artificial sweeteners may even impact your brain, Dr. Ogunyemi says, causing inflammation that can affect learning and memory.

You may need to consume a lot of artificial sweeteners before you experience these types of negative side effects. And yet, it's still important to remember they may not always be the "healthier" alternative to sugar.

It can be tough to find the time to read food labels, in order to know exactly what you're eating. But you should still try, whenever possible, to go for more natural or "whole" foods that have fewer artificial food additives — since these things can have an impact on your health.

Think along the lines of monosodium glutamate (MSG), artificial food coloring (like Blue 1 or Red 40), sodium nitrite, guar gum, carrageenan, and other artificial additives.

"The most significant reason to avoid artificial food additives [...] is that when we metabolize them, they release free radicals into the body that damage our cells," health and nutrition researcher Liana Werner-Gray, tells Bustle. "This process, known as oxidative stress, is a key factor in disease."

Again, it's fine to eat foods with additives in moderation. But keep this information tucked in the back of your brain, and make sure you eat plenty of natural foods, too.

"Healthy fats reduce inflammation while trans fats can increase inflammation," Werner-Gray says.

There are plenty of healthy fats that your body needs, which you'll find in the likes of olive oil, wild-caught salmon, seeds, and organic egg yolks, Werner-Gray says.

"Trans-unsaturated fatty acids, or 'trans fats,' are industrially produced fats that are used as a basis of margarine and other dietary fat additives," Bart Wolbers, MS, researcher at Nature Builds Health, tells Bustle.

While trans fats weren't always considered unhealthy, we now know that "trans saturated fatty acids increase the risk for heart disease, may confer diabetes risk, [...] damage the liver, [and has even been] linked to depression," Wolbers says.

The best way to avoid them is by reading food labels, avoiding "man-made foods," Wolbers says, and creating your own meals by combining "single ingredients" as often as possible, so you have more control over what you're eating.

"Smoked and preserved meats, like deli meats and jerky, are notoriously bad for our health," Dr. Ogunyemi says. "They contain polycyclic aromatic hydrocarbons, compounds that have been linked to a variety of cancers, such as stomach cancer and breast cancer," according to some research.

While we often don't think twice about charring meat on the grill, or putting deli slices on a sandwich, "these meats are also associated with chronic problems, like diabetes and heart disease," Dr. Ogunyemi says.

As with anything, it's all about moderation. But do keep in mind that the charred bits on your steak may not be the best for your health. And the same is true for deli meats packed with preservatives.

While super convenient, frozen entrees aren't always the best for your health. "Most frozen entrees are saturated with [...] sodium, and way more than what our daily diet intake should be," Barbara Rich, lead chef of Health-Supportive Culinary Arts at the Institute of Culinary Education, tells Bustle. Some frozen dinners even contain double the amount of sodium you're supposed to eat in an entire day.

They're OK to have in a pinch, as long as you keep in mind how much sodium you're getting. "The American Heart Association recommends no more than 2,300 milligrams a day and moving towards an ideal limit of no more than 1,500 mg per day for most adults," cardiologist Dr. Garth Graham, tells Bustle, "while on average most Americans eat more than 3,400 mg per day."

Lowering your sodium intake, Dr. Graham says, can help lower your blood pressure and prevent hypertension.

Processed foods are everywhere, and include "popular items like convenience foods, snack cakes, sodas, juices, potato chips, and breakfast cereals," Dr. Josh Axe, D.N.M., C.N.S., D.C., founder of Ancient Nutrition and author, tells Bustle.

While the occasional snack won't hurt you, these foods can contribute to inflammation in the body, Dr. Axe says, "and even lead to things like chronic pain."

"For this reason," he says, "minimizing your intake [of] processed foods is consistently recommended to help manage painful conditions like arthritis and inflammatory bowel disease."

If you have health issues, it may be even more important to watch what you eat, and pay close attention to ingredients like trans fat or food additives. But this advice can apply to anyone.

Even though most foods are fine to eat in moderation, some can contribute to inflammation and other health issues, that can make you sick in the future. And paying attention to what they are, and how often you eat them, can be a big part of staying healthy.