If ever you find yourself (or your tummy) grumbling for food even when you just ate, you're not alone.

Studies show that there are certain food groups that spike your appetite, making it harder for you to stick to your New Year's resolution of losing weight. So, ditch these unhealthy foods and say goodbye to those unwelcome cravings. Read on!

1.      Cheese

This one goes back to when you were still an infant. "Humans are programmed to have an opioid (opiate-like) response to a protein found in milk (casein) so that infants will continue their desire to consume adequate amounts of their mother's milk," elaborates JulieannaHever,  MS, RD, CPT, a plant-based dietitian and author of The Vegiterranean Diet and The Complete Idiot's Guide to Plant-Based Nutrition. "Cheese, which is a concentrated form of milk, also induces this effect. These protein compounds, called casomorphins, combined with the high amount of fat and salt are what is responsible for the popular obsession with cheese. Thus, the more you have, the more you crave-as devised by nature." No wonder it's hard to stop at just one slice of pizza.

2.      Low-Fat Yogurts

While yogurt is often marketed as a healthy fridge staple, it's not always the case. "It truly depends on which one you choose to keep you full," says Nutritionist Kayleen St. John, RD of Natural Gourmet Institute in New York City. "A typical 6-ounce fruit-on-the-bottom yogurt clocks in at 150 calories, 6 grams protein, 1.5 grams fat and around 25 grams sugar. The higher carbohydrate load and very low-fat content will keep you looking for more to eat, even after your last spoonful." A better option would be to have a plain Greek-style yogurt that contains twice the protein. Add in your own fruit, nuts, and seeds for additional fiber and nutrients.

3.      Fat-Free Salad Dressings

The water content in those green leafy vegetables should make you feel fuller, right? What about your fat-free salad dressing? Lisa Hayim, registered dietitian and founder of The WellNecessities, says that, "When we grab for the fat-free bottle, we think we are making the good choice." But that is not always the case. "These fat-free salads dressings can be loaded with salt and sugar to give them flavor. We end up pouring on more, making sure each piece of lettuce in our salad is doused. After the salad is over, the salt and sugar make you feel unsatisfied and craving more." Want a flat belly? Read the labels.

4.      Artificial Sweeteners

Just when you thought you're in the clear, this one proves you wrong. "Artificial sweeteners trick your brain into thinking it is getting a pleasurable food. When you don't eat the real thing and your body is expecting it, you're likely to be left craving that sugary food even more," says Janel Funk, MS RD LDN. Artificial sweeteners also cause abdominal pain and discomfort, another reason to stay away from them.

5.      Store-bought Soups

Say you're on a diet, and you dash to your nearest grocery to pick up a can of soup. Soups can jumpstart your way to an amazing weight loss, right? Yes, when you are making them from scratch. But when picked up from a supermarket? Not really. "Soups oftentimes contain more sodium than any other food. The sodium in these [seemingly harmless cans] causes that feeling of addiction and wanting more and more," explains Hayim.