From the Guidelines
Weight gain that isn't fluid-related is primarily caused by an excess of calorie consumption compared to calorie expenditure, with key factors including poor dietary choices, sedentary lifestyle, hormonal imbalances, certain medications, genetic predisposition, poor sleep quality, and age-related metabolic slowdown. When you consume more calories than your body burns, the excess is stored as fat tissue. Common causes include poor dietary choices such as consuming high-calorie processed foods, sugary beverages, and large portion sizes, as highlighted in a study published in Circulation 1. Sedentary lifestyle with insufficient physical activity reduces calorie burning, contributing to weight gain. Hormonal factors can also play a significant role, including thyroid disorders (particularly hypothyroidism), polycystic ovary syndrome (PCOS), and hormonal changes during menopause. Certain medications like antidepressants (especially SSRIs like sertraline), antipsychotics (such as olanzapine), corticosteroids (like prednisone), and some diabetes medications (including insulin) can promote weight gain as a side effect, as noted in a review published in JAMA 1. Genetic predisposition affects how your body stores fat and regulates appetite. Poor sleep quality and chronic stress increase cortisol levels, which can promote fat storage, particularly around the abdomen. Age-related metabolic slowdown also makes weight gain more likely as you get older due to decreased muscle mass and lower basal metabolic rate.
Some key points to consider when addressing weight gain include:
- Dietary choices: focusing on whole, unprocessed foods like fruits, nonstarchy vegetables, nuts, yogurt, fish, and whole grains, which can help protect against chronic weight gain 1
- Physical activity: increasing physical activity to complement dietary changes and support weight maintenance and metabolic health
- Medication management: being aware of the potential for certain medications to promote weight gain and discussing alternative options with a healthcare provider 1
- Sleep and stress management: prioritizing good sleep quality and finding healthy ways to manage stress, such as through exercise or mindfulness practices
- Genetic predisposition: understanding how genetic factors may influence weight gain and working with a healthcare provider to develop a personalized plan
Understanding these causes can help you address specific factors contributing to your weight gain through appropriate dietary changes, increased physical activity, and medical intervention when necessary, as discussed in a study published in the American Family Physician 1.
From the Research
Causes of Weight Gain that Isn't Fluid
- Excess calorie intake: Consuming more calories than the body needs can lead to weight gain 2, 3, 4, 5, 6
- Fat absorption: Inhibition of dietary fat absorption can reduce weight gain, as seen with the use of orlistat 2, 3, 4, 5, 6
- Metabolic factors: Improvements in metabolic risk factors, such as total and low-density lipoprotein cholesterol, blood pressure, and plasma glucose, can also contribute to weight gain or loss 2, 3, 4, 5, 6
- Medication effects: Certain medications, like orlistat, can affect weight by reducing fat absorption or improving metabolic parameters 2, 3, 4, 5, 6
Mechanisms of Weight Gain
- Dietary factors: High-fat diets can contribute to weight gain, while hypocaloric diets can lead to weight loss 2, 3, 4, 5, 6
- Physiological factors: Enzyme inhibition, such as lipase inhibition by orlistat, can reduce fat absorption and contribute to weight loss 2, 3, 4, 5, 6
Related Health Conditions
- Obesity: A condition characterized by excess body fat, which can increase the risk of various health problems 2, 3, 4, 5, 6
- Type 2 diabetes: A condition characterized by high blood sugar levels, which can be improved with weight loss and metabolic changes 2, 3, 4, 5, 6
- Metabolic syndrome: A condition characterized by a cluster of metabolic risk factors, which can be improved with weight loss and lifestyle changes 2, 3, 4, 5, 6