It’s no secret weight gain and overeating is an issue during the holiday season. Studies show many people start to gain weight in October, and the trend continues into January. Most individuals gain an average of 1.5 pounds during the holiday season. But it’s not just the weight gain that causes issues. Overeating affects the body in a variety of ways. It makes the digestive system work harder and can also lead to organ issues, as well. If overeating becomes a pattern, there are long-term consequences.

The Stomach Expands

A normal, adult stomach holds about two cups of food. The stomach is about the size of a fist when empty. When an individual eats too much, the stomach stretches beyond its normal size to allow room for the additional food, similar to the way a balloon expands if overfilled. The stomach presses against other organs, leading to discomfort and a feeling of fullness. The muscles in the stomach work harder to keep the food in place for the digestive process. However, after several months of overeating, the stomach muscles become accustomed to the stretching required and it takes more food to achieve a feeling of fullness.

Hydrochloric Acid and Reflux

The stomach produces hydrochloric acid to turn food into usable nutrients for the body. Overeating increases the risk of acid reflux and indigestion. Instead of moving through the digestive process, the food regurgitates from the stomach, backing up through the esophagus and leaving a bitter taste in the throat and back of the mouth. Holiday foods typically have higher fat content. Fatty foods cause the lower esophageal sphincter (LES) to relax instead of closing up. Normally, the LES closes to prevent food from moving up from the stomach into the esophagus. When overeating combines with a higher intake of fatty foods, the problem intensifies.

Overeating Slows Down Digestion

Digestion takes a great deal of energy, but overeating can cause the digestive system to slow down rather than speed up as you might think; this causes further discomfort. If a person vomits after overeating, it could indicate a condition called gastroparesis — the muscle contractions that help push food through the digestive tract have stopped working. Additionally, the digestive enzymes and acids produced in the stomach are in limited supply. Higher amounts of food take longer to digest and remain in the stomach for a longer period, causing a bloated, gassy feeling. An established pattern of overeating causes the food to turn into fat.

The Brain and Overeating

The sights and smells associated with holiday foods send signals to the brain, which then notifies the stomach that food is on the way. Researchers believe overeating may be linked to humans’ connection with comfort food. Holidays are full of comfort foods and family traditions, but they also tend to be stressful. Combine the two, and it’s easy to see how overeating occurs. While one large holiday meal is unlikely to cause major issues, it could trigger a cycle of overeating which could cause long-term impairment over time. Some studies link a high caloric intake with increased chances for mild cognitive impairment in mid-life and memory loss in later life.

Gastrocolic Reflex

Some people experience the need to go to the bathroom immediately after consuming a large meal. This is the gastrocolic reflex, which triggers a forward movement, or peristalsis, initiated in the colon. Overeating causes significant stretching in the stomach. Receptors located in the stomach signal the colon to create space for a large amount of food. High-calorie foods tend to spur peristalsis as well. However, people who eat small amounts and tend to snack during the holidays could also experience issues with the gastrocolic reflex. Nibbling small amounts of food throughout the day doesn’t allow enough stretching, so there is no triggering of the gastrocolic reflex and constipation could be the result.

Sleepiness

After eating, more blood is sent to the gastrointestinal tract, leaving less blood to transport the nutrients and oxygen required by the other parts of the body. This lack of blood can leave a person feeling sluggish, sleepy, or even lightheaded. Increased consumption of carbohydrates and sugars during a meal may also cause a spike in blood sugar, creating a burst of energy as the body produces and releases additional insulin to accommodate the intake of sugary foods. Soon after, however, the body crashes, causing weakness, irritability, or even a shaky feeling.

Food Hangovers

Overindulging is common during the holidays, especially with so much of the food consisting of fatty, salty, sugary, spicy or starchy ingredients. Just as alcohol can cause a hangover, so can too much of these types of foods. Food hangover symptoms include stomach pain, nausea, bloating, gas and other signs of digestive distress. Although food normally digests within two to six hours, fatty foods slow down the process, causing nausea, heartburn, and stomach discomfort that can linger throughout the night into the next morning. Eating salty foods may lead to water retention the following day, and eating a large amount of sugar can cause an individual to wake up cloudy-headed.

Late Night Binges and the Heart

Holiday parties and late night party binges can cause a serious case of indigestion. The combination of a big meal, alcohol, and caffeine often precedes acid reflux. Adding an over-the-counter pain reliever to ward off the next-day effects of the alcohol intensifies the issue because it irritates the esophagus. Late night overeating contributes to gastrointestinal overload, causing stress on the body that can affect the heart, resulting in racing or skipped heartbeats.

The Pancreas and the Liver

When the pancreas detects excess sugar in the blood, it begins pumping out insulin to remove it. Tes organ also produces specialized hormones to regulate the body’s functions. If there are high amounts of fat in the blood, it may lead to an inflammation of the pancreas. Although damage is not likely to occur from eating too much during a couple of holiday meals, continued high levels of fat in the blood can cause a chronic condition and permanent damage. The liver helps digest fats but can be damaged by overeating. Excessive alcohol consumption can cause fat deposits to accumulate in liver cells. The liver is unable to process more than one standard alcoholic drink per hour.

Recovering from Holiday Overeating

Getting back to a normal routine after the holidays is key to losing any extra pounds. Re-establishing a consistent eating pattern is a good start. Avoid skipping meals, which enhances cravings and increases the production of the hunger hormone, ghrelin. High-fiber vegetables move through the gastrointestinal tract at a much slower pace, enhancing feelings of fullness. Regular exercise helps to suppress ghrelin production, and studies show it decreases incidents of binge eating.