What Is Cortisol?
Cortisol is one of the main hormones your body releases to manage stress. According to endocrinologist Dr. Avantika Waring, cortisol is always naturally present in the body, but its levels rise and fall depending on the time of day and your overall stress levels. It helps regulate blood pressure and blood sugar—when your body is under stress, cortisol stimulates the liver and muscles to release glucose into the bloodstream for extra energy, while also raising blood pressure to quickly pump blood to muscles.
Dr. Andres Splenser, an endocrinologist, explains that normal cortisol production begins early in the morning before waking, preparing the body for the day, and gradually declines in the late afternoon and evening. This rhythm follows the circadian cycle, with cortisol peaking during daylight hours and dropping at night during rest.
How Does Cortisol Affect Weight?
Under normal circumstances, cortisol does not directly affect appetite. However, Dr. Splenser notes that when the body is under chronic stress from factors like sleep deprivation or excessive worry, persistently high cortisol levels can increase appetite—especially cravings for high-calorie foods. Long-term elevation also promotes fat storage in the abdominal area and interferes with insulin function, leading to insulin resistance, which raises the risk of type 2 diabetes and high blood pressure.
Dr. Maria Teresa Anton adds that cortisol influences weight through multiple mechanisms: it alters metabolism to favor energy storage over expenditure, and high cortisol prompts the liver to release more glucose, raising blood sugar and stimulating insulin secretion, which converts excess sugar into stored fat.
How to Know When Cortisol Levels Are High
Dr. Waring emphasizes the difference between stress-related temporary cortisol spikes and pathological overproduction. The latter may present with fat accumulation in the belly and face (especially cheeks and neck), acne, muscle weakness, skin changes, and headaches. If a doctor suspects a medical condition, they will order blood, saliva, and urine tests.
For most people with stress-induced temporary cortisol elevation, common symptoms include fatigue and difficulty losing weight despite proper diet and exercise. In these cases, formal cortisol testing is usually not needed, and lifestyle changes can help.
How to Balance Cortisol Levels
Endocrinologists agree that the following lifestyle adjustments can help maintain a healthy cortisol rhythm:
- Prioritize sleep: Follow your circadian rhythm—aim to sleep before 11 p.m. and get 7–9 hours of quality sleep.
- Exercise regularly: Moderate aerobic activities (e.g., brisk walking, swimming) and strength training help lower stress, but avoid overtraining.
- Eat a balanced diet: Reduce high-sugar and processed foods; increase fiber-rich vegetables, whole grains, and lean protein.
- Manage stress: Practice meditation, deep breathing, yoga, or connect with friends to relieve daily stress.
- Limit caffeine and alcohol: Excessive caffeine and alcohol can disrupt cortisol rhythms, especially in the afternoon and evening.
How to Prevent and Combat Weight Gain Due to Cortisol
If you already experience stress-related weight gain, in addition to the lifestyle changes above, consider:
- Keeping a food and mood diary to identify stress triggers.
- Working with a doctor or dietitian to create a personalized diet and exercise plan.
- Seeking medical evaluation if weight gain is accompanied by other symptoms (e.g., severe fatigue, skin changes) to rule out pathological causes.
The Xiaoshu Health App can sync with Apple Health to track relevant metrics such as sleep, heart rate, and activity levels, helping you scientifically manage stress and weight.