Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Weight gain is a tricky thing—while some might notice it in their arms or thighs, others tend to see it mostly around their belly. But why does this happen?
Studies show that the way your body stores fat is influenced by a combination of genetics, hormones, and lifestyle factors. It is not just about what you eat or how much you move; it is also about where your body decides to put the extra weight.
In this blog, we will dive into the science behind belly fat and explore how factors like stress, diet, and hormones play a key role in your body’s fat storage patterns.
Stomach weight gain refers to an increase in fat around your abdomen, which can appear as bloating or more noticeable belly fat. Your body decides where to store fat based on things like hormones, genetics, and lifestyle habits—it is different for everyone.
There are two types of belly fat: subcutaneous fat, which sits just under your skin, and visceral fat, which is deeper and wraps around your organs. While subcutaneous fat is what you see, visceral fat is the one to watch out for, as it is linked to health risks like heart disease and diabetes.
Figuring out why your stomach weight gain happens, whether it is diet, stress, or something else, can help you tackle it more effectively.
Gaining weight around your stomach can happen for a bunch of reasons, and understanding why can make it easier to tackle. Knowing the main causes of belly fat can help you take focused steps to manage it. Let us break down what might be going on and how to get to the root of it!
A diet high in processed foods, sugar, and unhealthy fats can cause your body to store fat around your stomach. Studies show that a diet rich in refined carbohydrates and trans fats can trigger fat accumulation in the abdominal area. When your body takes in more calories than it burns, it stores the excess as fat, often around your belly.
Without regular physical activity, your body struggles to burn the calories you consume. Sedentary living can result in fat accumulation, especially around the abdomen. Even moderate exercise, like brisk walking, can help reduce belly fat and improve overall health.
Stress leads to an increase in the hormone cortisol, which has been linked to fat storage around the belly. High cortisol levels combined with insulin can promote visceral fat accumulation, making stress management a key factor in reducing stomach weight gain.
Hormones play a crucial role in how and where your body stores fat. Imbalances in hormones like estrogen, progesterone, and testosterone can cause weight to settle in the stomach area. For example, during menopause, women often notice an increase in abdominal fat due to a drop in estrogen levels.
Your genes can influence how and where your body stores fat. If your family tends to carry weight around the stomach, you may be more likely to do the same. Research indicates that certain genetic factors can influence fat distribution, with some people more predisposed to belly fat than others.
When your body becomes resistant to insulin, it can lead to increased fat storage around the abdomen. Insulin resistance is often linked to type 2 diabetes and obesity. Studies have shown that people with insulin resistance tend to accumulate more visceral fat, which can increase the risk of heart disease and metabolic disorders.
Drinking too much alcohol is another factor in stomach weight gain. The term ‘beer belly’ isn't just a myth—alcohol can contribute to fat storage, especially around your midsection. Excessive alcohol intake can lead to an increase in abdominal fat, as the body prioritises metabolising alcohol over other nutrients.
Not getting enough sleep or having poor-quality sleep can disrupt hormones like leptin and ghrelin, which regulate hunger and appetite. This can lead to overeating and, ultimately, more fat storage around the stomach. Research suggests that poor sleep is associated with an increase in abdominal fat, even in those who maintain a healthy weight overall.
As we age, our metabolism naturally slows down, making it easier to gain weight, especially around the stomach. Abdominal fat increases significantly with age, particularly for women after menopause, due to changes in hormones and a decrease in muscle mass.
Spending long periods sitting can slow your metabolism and increase fat storage. A sedentary lifestyle, especially combined with poor eating habits, is a major contributor to gaining weight around your stomach. Reducing sitting time and increasing physical activity can help reduce abdominal fat.
Simply eating more food than your body needs can lead to weight gain, and when that weight accumulates, it tends to settle around the stomach. Overeating, especially foods high in sugar and fat, can cause a spike in insulin and fat storage, leading to abdominal fat accumulation.
Protein is essential for building muscle and promoting fat loss. A diet low in protein can make it harder to maintain muscle mass and burn fat. People who eat a higher proportion of protein tend to have less belly fat, as protein helps regulate hormones that control appetite and fat storage.
An unhealthy gut microbiome can contribute to weight gain, especially in the abdominal area. Imbalances in gut bacteria may affect how your body stores fat, including in your belly. A diverse and balanced microbiome is crucial for maintaining a healthy weight and digestion.
Certain medications can lead to weight gain as a side effect, particularly those that affect your metabolism or appetite. Medications like antidepressants, corticosteroids, and insulin can increase the likelihood of storing fat around your stomach. Always check with your doctor if you suspect your medication is affecting your weight.
A slow metabolism means your body burns fewer calories at rest, which can contribute to weight gain, especially around the belly. As you age, your metabolism naturally slows, but factors like genetics, diet, and exercise can also impact your metabolic rate. A slower metabolism can lead to more fat storage, particularly in the abdominal area.
Gaining weight in your stomach can have a bigger impact than you might think. It is not just about appearance—it is closely tied to your health and quality of life. Below are some key ways excess abdominal fat can affect you:
Excess stomach fat, especially visceral fat, is closely associated with heart disease. Visceral fat produces inflammatory markers and can contribute to high blood pressure, high cholesterol, and artery damage.
Abdominal fat plays a significant role in insulin resistance, a major factor in developing type 2 diabetes. People with a higher waist-to-hip ratio are more likely to have issues with blood sugar regulation, making belly fat a red flag for metabolic health.
Extra weight around the stomach can shift your body’s centre of gravity, thus putting additional strain on your lower back and core muscles. Over time, this can lead to poor posture and chronic back pain, so everyday activities become uncomfortable.
Excess stomach weight can limit your range of motion and reduce endurance, making it harder to stay active. Activities like running, bending, or even climbing stairs may feel more strenuous, creating a cycle where less activity leads to further weight gain.
For many people, gaining stomach weight can affect their confidence and self-image. This can lead to feelings of frustration, self-consciousness, and even anxiety, especially if the weight gain feels beyond their control.
Visceral fat isn’t just stored energy; it is metabolically active and produces inflammatory substances. Chronic inflammation caused by excess abdominal fat has been linked to conditions like arthritis and autoimmune diseases.
Stomach fat has also been linked to a higher risk of some cancers, including colorectal and breast cancer. Research suggests that inflammation and hormonal changes caused by visceral fat may contribute to cancer development.
Addressing belly fat is all about small, intentional changes that add up over time. These six tips are practical, straightforward, and easy to follow:
Focus on a Balanced Diet: Fill your plate with veggies, lean proteins, and healthy fats to give your body the nutrients it needs.
Incorporate Regular Exercise: Blend cardio and strength training to burn calories and build muscle for a stronger, leaner core.
Manage Stress Effectively: Stress can lead to belly fat, so unwind with activities like yoga, deep breathing, or even journaling.
Get Adequate Sleep: A good night’s sleep isn’t just refreshing; it also helps regulate hormones that affect fat storage.
Avoid Sugary and Processed Foods: Cut back on these sneaky calorie bombs to reduce fat accumulation around your midsection.
Stay Consistent with Healthy Habits: Consistency is key. Stick to your plan, and over time, you will see progress.
Stomach fat often results from a mix of diet, lifestyle, and biological factors. Poor eating habits, lack of exercise, stress, and sleep issues can all contribute, as can genetics, hormones, and ageing. Understanding these causes is the first step to addressing them. By making targeted changes like improving your diet, staying active, and managing stress, you can work towards reducing belly fat and improving your overall health.
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.