Why do cooked tomatoes upset my stomach

Some people treat their bodies like a Ferrari; others, like a clunker. A Ferrari body is given a healthy diet with the right mix of carbohydrates, fats, proteins, water, salts, vitamins, and soluble and insoluble fiber — all requirements for avoiding indigestion. “If you’re missing any of those, it’s a problem,” says Benjamin Krevsky, MD, MPH, director of gastrointestinal endoscopy and professor of medicine at the Lewis Katz School of Medicine at Temple University in Philadelphia.

Getting the right fuel enables the body to work more efficiently. And when you’re having indigestion, which includes symptoms like nausea and bloating, what not to eat becomes just as important. Here are foods to avoid when you’re having tummy troubles.

One food group that can be hard to digest is dairy, mainly because of lactose, the sugar found in milk and other dairy products. When lactose isn’t digested properly, such as in people with lactose intolerance, gas and bloating result. If you consume too much lactose, it goes into the large intestine, and diarrhea can develop or worsen. When you're dealing with digestive problems, it may still be okay to eat yogurt and hard cheeses because they have no lactose, or you can try lactose-free milk.

Tomato sauce and citrus fruits, such as lemons, limes, oranges, and grapefruit, are acidic and can irritate the stomach lining, causing digestive problems. Many people don’t realize that carbonated beverages are also acidic. When you have an upset stomach, avoid acidic foods, says Krevsky.

Fatty foods stimulate contractions in the digestive tract, which can either slow down the emptying of the stomach and worsen constipation, or speed up movement, leading to or worsening diarrhea. The effect can depend on the type of fat and your tendency toward constipation or diarrhea. When you’re experiencing a bout of indigestion, put low-fat foods on the menu and eat small meals spaced throughout the day, which can put less pressure on your stomach. Avoid high-fat culprits, like butter, ice cream, red meat, and cheese, at least for a while.

The problem with fried foods is the same as with fatty foods — they can move, undigested, through the body too quickly, leading to diarrhea, or stay in your digestive tract too long, causing you to feel full and bloated. Many fried foods are low in fiber and take longer to digest. So if you’re dealing with either diarrhea or constipation, you’ll want to avoid fried foods for a while. The conventional wisdom, according to Krevsky, is that when you have indigestion, you should avoid fried foods because they tend to slow down the emptying of the stomach.

If you’re constipated, you should avoid processed foods because they lack fiber, which helps regulate bowel movements, Krevsky says. Processed foods also often contain preservatives and artificial coloring, Kim says, and people with allergies or sensitivities to these additives will feel their effects during bouts of digestive trouble. Note that some packaged foods also contain lactose, which can give you gas and worsen any discomfort you’re already going through.

The artificial sweetener perhaps most associated with digestive problems is sorbitol. It's a hard-to-digest sugar found naturally in some fruits, including prunes, apples, and peaches, and is also used to sweeten gum and diet foods. Once sorbitol reaches the large intestine, it often creates gas, bloating, and diarrhea. If you have diarrhea, read food labels so that you can avoid sorbitol, Krevsky says.

If you’re feeling nauseated, the last thing you should have is an alcoholic drink. “It will probably make you sicker,” Kim says. As Krevsky explains, alcohol is toxic to the stomach lining and changes liver metabolism. Drinking too much can cause indigestion, among other health problems. Moderation is key.

Caffeine stimulates gastrointestinal tract motility, making contents move more quickly through your system, and excessive amounts can give anyone diarrhea, Krevsky says. So if you already have diarrhea, caffeine will only worsen your digestive problem. He also warns against simply switching to decaf coffee because it still has some caffeine. Remember that tea, soda, and chocolate are other sources of caffeine, and should be put on hold until tummy troubles go away.

The body doesn’t like trying to digest foods that are super sweet or salty — it likes moderation. When you’re sick, “You want something that’s easily digested,” Kim says. “Some people are affected by sugar levels when they are nauseous.” Chocolate, a sweet-tooth favorite, can be a culprit in many digestive problems, including heartburn and the more serious GERD (gastroesophageal reflux disease).

Many refrigerated foods can go bad, such as dated items like eggs, dairy products, and meat. Bacteria like salmonella and E. coli can also pass from raw meat to veggies and fruits. Eating tainted foods can cause digestive problems or worsen existing ones, including diarrhea and vomiting. Be aware of the symptoms of food poisoning — muscle pain, fatigue, and abdominal cramps — because food poisoning can be life threatening, Krevsky says.

If you're experiencing nausea, vomiting, and diarrhea, you’ll want to avoid food choices that stimulate the digestive system, and these include spicy foods, says Jung Kim, a registered dietitian and specialist with Clinical Nutritional Support Services at the Hospital of the University of Pennsylvania in Philadelphia. Spicy foods are “incredibly variable,” says Dr. Krevsky — they have no effect on some people, but cause indigestion for others. In general, you should choose bland foods when you’re having digestive problems, and be sure to avoid spices if you’re sensitive to them.