When most people experience rapid weight gain, they tend to look at external factors. Maybe someone is injured and unable to exercise as much as they used to, resulting in sudden weight gain. Perhaps they’re going through a rough time and turn to food for comfort, gaining weight fast.
Sometimes the causes of weight gain are outside of your control. In fact, certain medical issues and prescription medications can cause rapid weight gain. Regardless of the cause, the most important thing is to recognize what is happening, identify the cause, and take control of the situation.
Even if the excess weight gained is the result of a medical condition, it needs to be addressed before the weight causes more health problems (known as comorbidities). Approximately one-third of the entire US population is overweight (with the numbers increasing every year) (1).
Without considering pre-existing health problems, excess weight and obesity put you at risk – or at an increased risk – for all of the following (2):
- Heart disease
- Bone and joint problems
- Type 2 diabetes
- Sleep Apnea
- Cancer (certain types)
- Metabolic Syndrome
- Kidney Disease
- Fatty Liver Disease
21 Causes of Rapid Weight Gain
If you’re unsure what may be causing your weight gain, the list below should help you narrow it down. Please remember that you should consult your primary care physician with any weight gain (or sudden weight loss) concerns.
1. A Slow Thyroid
Known as hypothyroidism, an underactive thyroid is one of the most common causes of unexpected and rapid weight gain (3). The hormones excreted by the thyroid gland play a huge role in your metabolism. Without sufficient levels of thyroid hormone in the blood, the metabolism slows down and can lead to weight gain.
Even among all of the inconsistencies in the science of nutrition, there is one rule that is indisputable: if you eat more calories than you burn, you will gain weight.
This means that even if you are eating a completely clean diet, you can still gain weight if you don’t watch your portions. Never assume that a food is low-calorie just because it’s healthy – always double check the nutritional values.