Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Stress is often seen as just a mental struggle, but it has real physical consequences, including weight gain. When you’re constantly stressed, your body releases cortisol, a hormone that increases appetite and promotes fat storage, especially around the belly. Research even links chronic stress to higher body weight and a greater risk of obesity.
But hormones aren’t the only problem. Stress can wreck your sleep, slow down your metabolism, and lead to emotional eating. If you’ve been struggling with weight gain despite your best efforts, stress might be the sneaky culprit. Let’s break down why this happens and how you can stop stress from sabotaging your health.
Stress can come from anywhere—work, relationships, finances, and even big life changes. While some stress is normal, constant pressure can take a toll on your body and mind. Below are some of the most common stress triggers.
Long hours, tight deadlines, and high expectations can make work a major stressor. A study found that job-related stress increases the risk of obesity. When work takes over, self-care, exercise, and healthy eating often take a backseat.
Money troubles can be a huge source of stress, triggering sleepless nights and unhealthy coping mechanisms. Research shows that people under financial stress are more likely to skip meals or rely on cheap, processed foods that lead to weight gain.
Arguments, breakups, or family tensions can cause chronic stress, which can affect eating habits. Some people lose their appetite, while others turn to comfort foods high in sugar and fat. Either way, stress disrupts normal eating patterns.
Worrying about your own health or a loved one’s condition can be overwhelming. Chronic illnesses, pain, or medical bills can all add to stress levels, making it harder to maintain a balanced lifestyle.
When work spills into personal time, stress levels rise. If you're constantly on your phone checking emails or bringing work home, your body never gets a chance to relax. This can lead to exhaustion, poor food choices, and less time for physical activity.
Moving, getting married, having a baby, or losing a loved one—all of these can be emotionally draining. Even positive changes can be stressful. Big life events can throw off routines, making it harder to maintain healthy habits.
When stress becomes a daily battle, your body responds in ways that can lead to weight gain. Cortisol spikes, cravings intensify, and metabolism slows down. Over time, these effects add up, making it easier to gain weight and harder to lose it.
Stress also affects the way your body stores fat. Studies show that high cortisol levels promote fat storage around the abdomen, increasing the risk of heart disease and type 2 diabetes. On top of that, stress impacts digestion—some people experience bloating or sluggish digestion, while others develop gut issues that make weight management even trickier. When stress lingers, it doesn’t just mess with your mind; it rewires your entire body’s response to food, energy, and fat storage.
Stress doesn’t just make you feel overwhelmed. It also changes the way your body processes food, stores fat, and burns calories. Chronic stress can create the perfect storm for weight gain.
Increased Cortisol Production
Cortisol, the body's main stress hormone, plays a big role in weight gain. It signals the body to store fat, especially in the belly area. High cortisol levels are linked to increased abdominal fat, which is the most harmful type of fat for overall health.
Stress doesn’t make you crave salad—it makes you want sugar, salt, and fat. This is because cortisol triggers the release of ghrelin, the hunger hormone, which increases cravings for calorie-dense foods. That’s why stress eating often leads to weight gain.
Chronic stress can mess with your sleep, and poor sleep is directly linked to weight gain. Sleep deprivation affects hormones that control hunger, making you more likely to overeat. Plus, when you're tired, you're less likely to exercise and more likely to reach for quick, unhealthy snacks.
Long-term stress can affect your body's ability to manage weight in several ways. While stress hormones like cortisol can influence appetite and fat storage, stress may also contribute to habits that impact metabolism, such as poor sleep, lower physical activity, and unhealthy food choices.
If you’re wondering whether stress has slowed your metabolism, check out these common signs.
Stress can make food feel like a quick escape. When emotions take over, eating becomes less about hunger and more about comfort. This often leads to overeating, especially foods high in sugar and fat, which contribute to weight gain.
Managing stress isn’t just about feeling better—it’s about preventing the physical effects, including weight gain. Here are some science-backed ways to keep stress in check and maintain a healthy weight.
Physical activity helps lower cortisol levels and boosts endorphins, which improve mood. Even a 30-minute walk can reduce stress and prevent stress-related weight gain.
Eating a diet rich in protein, fibre, and healthy fats can help stabilise blood sugar levels and reduce cravings. Omega-3s, found in fish and nuts, have been shown to lower cortisol levels.
Good sleep is essential for stress management and weight control. Aim for 7–9 hours of quality sleep each night to keep hunger hormones balanced and energy levels high.
Mindfulness practices like meditation and yoga have been proven to lower stress hormones and reduce emotional eating. Deep breathing exercises can also help calm the nervous system.
Trying to do everything at once only adds to stress. Break tasks into smaller steps and focus on what truly matters. A well-organised routine can reduce anxiety and prevent stress from taking over.
Talking about stress can help relieve it. Whether it’s a chat with a friend, a support group, or therapy, having a strong support system can make stress feel more manageable.
While coffee and sweets might give you a quick energy boost, they also spike cortisol levels. Cutting back on stimulants can help keep stress and weight gain under control.
Stress is unavoidable, but its effects on your weight don’t have to be. By understanding how stress triggers weight gain and taking proactive steps to manage it, you can stay in control of both your mental and physical health. Small changes like getting enough sleep, eating well, and finding time to relax can make a big difference in preventing stress from taking a toll on your body.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.