If you want a flatter stomach, these are the six worst ways to eat

You might not even realize it, but these daily habits could be getting in the way of your weight loss goals.

If you want a flatter stomach but aren't getting there, a bad diet and bloating could be to blame.

"We know that extra calories from big portions and sugary drinks can lead to more belly fat, which makes it hard to get a flatter stomach," says Amber Pankonin, MS, RD, owner of the Stirlist and registered dietitian. "Bleeding or a swollen stomach can be caused by problems with digestion, intolerances to certain foods, or not getting enough of a certain nutrient."

Bonnie Taub-Dix, RD, who runs the website Better Than Dieting and is a registered dietitian, says, "Constipation could also make you feel puffy, and you might mistake bloat for belly fat."

Dietitians say that these six eating habits may be keeping you from reaching your goals, especially if you are trying to lose weight around your middle or just can't get a flat stomach. Read on, and check out 57 Healthy Weight Loss Dinner Recipes for Super Busy Week Nights for more healthy eating tips.

1. Not enough fiber in your diet.

If you don't eat enough fiber every day, your stomach might get too big. Pankonin says that not getting enough fiber in your diet can cause constipation or other digestive problems. "Fiber can help move things along in the gut, which makes it easier to go to the bathroom and lessens bloating."

If you're not sure if you're getting enough fiber every day, the Mayo Clinic says that women should try to eat 21–25 grams and men should aim for 30–38 grams.

2. Getting too little protein.

If you don't get enough protein, it could make your stomach bigger and make it harder to get a flatter stomach.

Pankonin says that protein helps keep the body's fluid balance in check. "If you eat too many simple carbs and not enough protein, you might keep water in your body and get bloated."

The Mayo Clinic says that an average sedentary adult should eat 0.8 grams of protein per kilogram of body weight to keep from getting too little protein. For instance, a person who weighs 75 kilograms (165 pounds) should eat 60 grams of protein every day.

This can change, though, based on your age and how much you do. Your body needs more protein as you get older to keep from losing muscle mass, which the Mayo Clinic says starts between 40 and 50 years of age. If this is you, you need about 1–1.2 grams of protein per kilogram of body weight.

They also say that you need about 1.1–1.5 grams per kilogram if you work out often. People who do high-impact exercises like lifting weights, running, or cycling may need 1.2–1.7 grams per kilogram.

3. Gum, especially gum without sugar.

You might chew gum to get rid of food cravings or stop yourself from snacking too much, but it could also be making your stomach bloat.

"When you chew gum, you swallow air, which can lead to bloat and pain," says Taub-Dix. "Sugar-free gums are often made with sugar alcohols, which can cause bloating, stomach pain, gas, and even diarrhea in some cases."

4. Straws are used to drink.

When you drink through a straw, you can get very bloated. So, if you want a flat stomach, you might want to skip the straw the next time you drink.

Taub-Dix says, "Every time you drink through a straw, it's like blowing air into a balloon. You're pumping air into your gut." "When you drink carbonated drinks, this process gets even worse. You should bring the glass or bottle to your lips and take small sips."

5. Having too many drinks with carbonation.

Unfortunately, if you drink a lot of seltzer or soda, you may also be getting a lot of gas.

"Carbonated drinks, even diet ones, add bubbles to your gut, which can make you feel like your stomach is getting bigger," says Taub-Dix. "Some carbonated drinks, like sparkling water, could be healthy. However, if you are sensitive and often feel bloated, still, non-carbonated water might be best for you."

6. Drinking too much alcohol.

Too much alcohol can make you gain belly fat, which might be stopping you from getting the flat stomach you want.

"Drinking too much alcohol is linked to weight gain and a bigger waistline because alcohol has no nutritional value," says Pankonin. "It's also important to think about the foods that are often eaten with alcohol, like fried or salty foods, which can often make you feel bloated."

One study also found that alcohol may make people eat too much by waking up nerve cells in the brain that are linked to a bigger appetite.