We’ve all heard it before – weight gain is simply a problem of too many calories consumed and too little calories burned. While calorie balance obviously plays a big role, it’s not always that simple. When thinking about weight gain in the abdomen specifically, it becomes even more complex. Hormones, stress, sleep, genetics, aging, inflammation, play a role in the distribution of fat on the body. Understanding how each of these influences work can help explain why abdominal fat can be hard to get rid of, and can potentially help you adjust your approach for a more successful outcome.
Abdominal fat can be of two types, each with distinct risks. The less risky type of abdominal fat is called subcutaneous fat, which is fat tissue stored just beneath the skin. This type of fat is typically softer; you may be able to pinch it around the waist. The riskier type to have is called visceral fat, which is fat tissue stored deeper in the abdomen around vital organs. Visceral fat is strongly associated with increased risk for cardiovascular disease, insulin resistance, type 2 diabetes, and chronic inflammatory conditions. One of the many mechanisms making visceral fat more risky is that it releases inflammatory molecules and hormones directly into the bloodstream from the liver. More visceral fat can disrupt blood sugar regulation, cholesterol metabolism, and overall metabolic health, which can often lead to even more accumulation of visceral fat. It can become a vicious cycle [1].
Your Hormones
Fat storage is influenced by a variety of hormones in the human body. Some of the key players that directly affect where fat accumulates include cortisol, estrogen/progesterone and insulin.
Cortisol, or the “stress hormone,” is one of the strongest hormonal causes of abdominal fat accumulation. When the body experiences chronic stress, cortisol levels remain elevated for extended periods. Stress is a major contributor, but other things such as lack of sleep, overexercise, certain medical conditions and medications can influence cortisol as well. Chronically elevated cortisol increase appetite and cravings for calorically dense foods (think high fat and sugar processed foods). Cortisol also encourages fat storage in the abdominal region, and can directly affect other hormones, like insulin [2].
Insulin regulates our blood sugar by helping glucose move from our blood after consuming food and drinks, into our cells for energy (or storage for later use). But when the body is repeatedly exposed to high blood sugar levels , which is most commonly caused by excess calories, processed foods, or a sedentary lifestyle, cells may become less responsive to insulin. At this point, the pancreas makes more insulin to get our cells to respond. This condition is called insulin resistance. In the presence of high levels of insulin in the blood, our bodies tend to store more fat, specifically the risky visceral fat discussed above. The vicious cycle can begin, in which visceral fat worsens insulin resistance, which then promotes even more abdominal fat storage [3].
Estrogen and progesterone also influence the location of fat on the human body, specifically in women. As many women have experienced, weight distribution tends to change in midlife, when estrogen and progesterone decrease with menopause. Estrogen and progesterone allow for weight distribution in the legs and hips, and when they decrease, women tend to notice more belly fat, even if they’ve never carried fat in their abdomen their whole life [4].
Some other notable hormonal influences on belly fat include leptin and ghrelin, which regulate our hunger and satiety cues. These hormones don’t specifically cause weight redistribution, but they definitely can influence overall accumulation of fat, and lifestyle is incredibly important for their regulation [5].
What Else?
Sleep
Research consistently shows that people who sleep fewer hours tend to have greater abdominal fat accumulation over time. Lack of sleep affects leptin and ghrehlin, insulin and cortisol. Not only that, sleeping less [6].
Age
As people age, body composition naturally shifts unless special effort is taken to prevent it. Muscle mass tends to decline while fat mass increases. Muscle loss is associated with a lower basal metabolic rate (fewer calories burned at rest), which can lead to fat gain despite maintenance of regular habits [7].
Inflammation
Fat tissue functions like an endocrine organ, releasing signaling molecules called cytokines. Excess visceral fat can produce chronic low-grade inflammation, which has been linked to several kinds of disease (like heart disease, cancer, fatty liver and diabetes). This inflammatory state may also influence appetite regulation and metabolic efficiency, making weight management more difficult. Not only can visceral fat create inflammation, inflammatory conditions can also make it more difficult to get rid of visceral fat through hormonal shifts and for many, a reduced ability to exercise [8].
Gut Microbiome
The gut is full of microbial species that can alter where we store fat tissue. It has been welldocumented that imbalanced ratios between certain gut bacteria are a contributor to metabolic dysfunction and weight gain. The balance of bacteria in the gut can affect how we extract calories from food, regulate out hunger and satiety hormones, and impact our sensitivity to insulin. Gut bacteria can even contribute to the body’s total inflammatory load, making it more difficult to maintain a healthy body weight and stave off visceral fat [9].
What can I do about it?
Research supports several basic, evidence-based strategies for reducing visceral fat:
1. Get moving! A combination of cardiovascular and weight training can help you shed stubborn visceral fat.
2. Increase protein intake, but not too high. Protein is necessary for building muscle, which functions at a high metabolic rate to help you expend more calories at rest.
3. Stress less. Incorporating techniques such as breathing exercises, meditation, journaling or therapy can help you calm stress hormones.
4. Don’t skip sleep. Maintaining regular sleep times, ensuring proper sleep hygiene, and prioritizing sleep over other things will help you avoid unwanted hormonal shifts.
5. Focus on gut-supportive, anti-inflammatory foods. Keeping inflammatory foods as low as possible (think saturated fats, refined carbohydrates, alcohol, and highly processed snack foods) while ensuring you’re consuming adequate amounts of fiber, fermented foods, and polyphenols (the healthy chemicals found in fruits and vegetables) is critical to your success at reducing abdominal fat gain. What you eat matters just as much as the amount you eat!
Abdominal weight gain is not driven by one single factor, but several factors that affect each other. It’s not always a reflection of willpower, or caloric balance! If you’re looking to learn more about visceral weight gain and better understand what is influencing your specific case, book an appointment with our Naturopathic Doctors to start investigating today!
References
[1] Bergman, Richard N., et al. “Why visceral fat is bad: mechanisms of the metabolic syndrome.” Obesity 14.S2 (2006): 16S-19S.
[2] Anagnostis, Panagiotis, et al. “The pathogenetic role of cortisol in the metabolic syndrome: a hypothesis.” The Journal of Clinical Endocrinology & Metabolism 94.8 (2009): 2692-2701.
[3] Cefalu, William T., et al. “Contribution of visceral fat mass to the insulin resistance of aging.” Metabolism 44.7 (1995): 954-959.
[4] Lovejoy, Jc Champagne, et al. “Increased visceral fat and decreased energy expenditure during the menopausal transition.” International journal of obesity 32.6 (2008): 949-958.
[5] Verdeş, G. A. B. R. I. E. L., et al. “Correlation between leptin and ghrelin expression in adipose visceral tissue and clinical-biological features in malignant obesity.” Rom J Morphol Embryol 58.3 (2017): 923-929.
[6] Giannos, Panagiotis, et al. “Shorter sleep duration is associated with greater visceral fat mass in US adults: findings from NHANES, 2011–2014.” Sleep medicine 105 (2023): 78-84.
[7] Hunter, Gary R., Barbara A. Gower, and Brandon L. Kane. “Age related shift in visceral fat.” International journal of body composition research 8.3 (2010): 103.
[8] Fontana, Luigi, et al. “Visceral fat adipokine secretion is associated with systemic inflammation in obese humans.” Diabetes 56.4 (2007): 1010-1013.
[9] U-Din, Mueez, et al. “Characteristics of abdominal visceral adipose tissue, metabolic health and the gut microbiome in adults.” The Journal of Clinical Endocrinology & Metabolism 109.3 (2024): 680-690.