Here is information you should know with how bariatric surgery changes your body

How Bariatric Surgery Changes Your Appetite And Metabolism?

Bariatric surgery, including gastric sleeve (sleeve gastrectomy), gastric bypass, and duodenal switch surgery, transforms your body in numerous ways beyond just reducing stomach size. These procedures not only aid in substantial weight loss but also significantly alter your appetite and metabolism, leading to improved overall health and quality of life. Lets read more below.

Table of Contents:

    Last Updated on May 27, 2024

    There are several types of weight-loss surgery, or bariatric surgery, including gastric sleeve (sleeve gastrectomy), gastric bypass, and duodenal switch surgery. In addition to making your stomach smaller or restricting the amount of food that enters your stomach, bariatric surgery changes your body in a number of ways.

    The more you learn about the different ways that bariatric surgery changes your body, both in helping get rid of excess weight and improving your quality of life, the more confident you can be in making the decision.

    Bariatric Surgery Impact On Your Hunger, Appetite & Metabolism

    weight set point theory stomach ghrelin cell metabolism body weight glucose metabolism gut hormone

    Bariatric surgery’s effects on appetite extend beyond stomach size reduction. For instance, gastric sleeve surgery reduces ghrelin production—a hormone that induces hunger—by removing the stomach portion that secretes it. This reduction leads to fewer hunger pangs and helps patients adhere to a reduced-calorie diet.

    Understanding Ghrelin: The Hunger Hormone

    Ghrelin, known as the “hunger hormone,” signals hunger to the brain. Post-surgery, lower ghrelin levels mean reduced hunger and easier diet adherence, aiding in significant weight loss.

    When the stomach is empty, ghrelin levels increase, prompting the sensation of hunger. Bariatric surgery, especially the gastric sleeve, involves removing a portion of the stomach that produces a significant amount of ghrelin.

    As a result, post-surgery patients experience a notable decrease in hunger pangs, making it easier to adhere to a reduced-calorie diet.

    bariatric surgery impact metabolism appetite

    Changes in Leptin and Other Satiety Hormones

    Leptin, produced by fat cells, signals satiety. Obesity often reduces leptin sensitivity, leading to overeating. Bariatric surgery helps restore leptin sensitivity, enhancing feelings of fullness.

    Additionally, hormones like Peptide YY and GLP-1, which promote satiety, increase post-surgery, further reducing appetite.

    The Role of Peptide YY and GLP-1

    Peptide YY and GLP-1 (Glucagon-like peptide-1) are hormones released by the intestines after eating and are crucial in promoting a sense of satiety. Bariatric surgery can increase the levels of these hormones, further contributing to reduced appetite and improved control over eating behaviors.

    Psychological and Behavioral Factors

    Hormonal changes are vital, but psychological and behavioral factors also play crucial roles. Post-surgery patients often receive counseling to develop healthier eating habits and a new relationship with food. Nutritional counseling helps patients adapt to reduced stomach capacity, ensuring they meet nutritional needs with smaller portions and nutrient-dense foods.

    The Importance of Nutritional Counseling

    Post-surgery, patients must adapt to a significantly reduced stomach capacity, which necessitates changes in eating patterns and food choices. Nutritional counseling is essential to ensure that patients meet their nutritional needs while adapting to their new appetite levels. This includes learning to recognize true hunger cues, understanding portion sizes, and choosing nutrient-dense foods to maintain energy levels and overall health.

    See also  What To Know Before Undergoing Gastric Sleeve Surgery

    Long-Term Effects and Monitoring

    The long-term effects of these hormonal changes are a subject of ongoing research. Most patients experience a sustained decrease in appetite and an improved ability to control their eating. However, regular monitoring and follow-up are crucial to address any nutritional deficiencies or adjustments in dietary habits as the body adapts over time.

    How Bariatric Surgery Affects Your Metabolism

    One of the least appreciated benefits of bariatric surgery is its effect on the metabolism of people with obesity. Excess weight and obesity can increase insulin resistance, inflammation and cell oxidation, all of which can negatively affect your energy levels and fat metabolism. So a positive side effect of weight reduction due to bariatric surgery is the improvement in your metabolism, which further helps you to lose weight.

    Enhanced Insulin Sensitivity

    One of the most significant metabolic changes post-bariatric surgery is the improvement in insulin sensitivity. Obesity is often associated with insulin resistance, a condition where the body’s cells don’t respond effectively to insulin, leading to elevated blood sugar levels. Post-surgery, as the body sheds excess weight, insulin sensitivity often improves, reducing the risk of type 2 diabetes and aiding in better blood sugar control. This change can be so profound that many patients with type 2 diabetes see a reduction or even remission of their condition.

    Reduction in Inflammatory Markers

    Chronic inflammation is a common issue in individuals with obesity, contributing to a range of health problems, including heart disease and metabolic syndrome. Bariatric surgery can lead to a significant reduction in markers of inflammation. This reduction is partly due to the decrease in fatty tissue, which is known to produce inflammatory substances. As inflammation decreases, the body’s overall metabolic health improves, enhancing energy levels and reducing the risk of various obesity-related conditions.

    Improvement in Fat Metabolism

    Obesity alters the body’s ability to metabolize fats efficiently. Bariatric surgery, by facilitating significant weight loss, can help normalize these processes. Improved fat metabolism not only contributes to further weight loss but also reduces the risk of fatty liver disease and improves lipid profiles, lowering the risk of cardiovascular diseases.

    See also  Why Am I Not Losing Weight On Ozempic?

    Changes in Gut Hormones and Microbiota

    Bariatric surgery also affects gut hormones and the microbiota, both of which play crucial roles in metabolism. Changes in the gut flora post-surgery can improve energy harvest from food and impact how nutrients and calories are absorbed. Additionally, alterations in gut hormones can enhance metabolic rate and energy expenditure, further supporting weight loss and metabolic health.

    Increased Basal Metabolic Rate (BMR):

    As patients lose weight post-surgery, there’s often an increase in the basal metabolic rate (BMR). This increase means the body uses more energy for basic functions at rest, which can contribute to further weight loss and help in maintaining the reduced weight long-term.

    Long-Term Metabolic Monitoring

    While the initial metabolic improvements post-surgery are significant, it’s essential for patients to engage in long-term monitoring. Regular check-ups and metabolic assessments ensure that these benefits are sustained and any potential deficiencies or issues are addressed promptly.

    The Role of Lifestyle Changes

    It’s important to note that while bariatric surgery initiates metabolic improvements, sustaining these benefits requires lifestyle changes. A balanced diet and regular physical activity are crucial in maintaining the improved metabolic state and ensuring overall health and well-being.

    How Bariatric Surgery Helps Improve Your Diet

    Another positive side-effect of bariatric surgery reported by participants in a number of studies is a change in the taste and even smell of certain foods following the procedure. As many as 97% of participants in one study reported at least one of the effects, which include an increased sensitivity to eating and drinking sweet, sour and/or fatty foods and beverages.

    The heightened sensitivity reduces your cravings for fast foods and sweet, high-carbohydrate foods and drinks. The same sorts of foods and drinks that are most often linked to weight gain.

    For more information, please contact our team at The Sleeve Clinic where we’ll be happy to provide you with more resources.

    Nutritional Guidance Post-Surgery

    Post-bariatric surgery, patients must adhere to a specific nutritional regimen to ensure proper healing and effective weight loss. This includes a diet rich in proteins, vitamins, and minerals, and low in sugars and fats. Emphasizing the importance of a balanced diet and regular consultations with a nutritionist can be a valuable addition to the content.

    Psychological Impact and Support

    The psychological impact of drastic weight loss and body changes post-surgery is profound. Addressing the need for psychological support and counseling can provide a holistic view of the journey. Discussing support groups and mental health resources can be beneficial for potential patients.

    See also  Mexico Gastric Sleeve Surgery - Should You Go & Risks Involved

    Physical Activity and Lifestyle Changes

    Incorporating content about the importance of physical activity post-surgery can be enlightening. Highlighting tailored exercise regimes and the role of physical activity in maintaining weight loss and overall health would be a valuable addition.

    Long-term Health Benefits

    Expanding on the long-term health benefits of bariatric surgery, such as improved cardiovascular health, remission of type 2 diabetes, and alleviation of sleep apnea, can provide readers with a comprehensive understanding of the surgery’s impact.


    1. What dietary changes are required after bariatric surgery?
      • “Post-surgery diets progress from liquids to pureed foods, then soft foods, emphasizing protein intake and hydration.”
    2. How long does it take to see the full benefits of gastric sleeve surgery?
      • “Full benefits, including maximum weight loss and improvement in comorbid conditions, are typically observed within 12 to 18 months post-surgery.”
    3. What psychological support is available for bariatric surgery patients?
      • “Many clinics offer counseling and support groups to help patients adjust psychologically to life after bariatric surgery and maintain weight loss.”
    4. Can bariatric surgery improve type 2 diabetes?
      • “Bariatric surgery can significantly improve or resolve type 2 diabetes by reducing body weight and altering gut hormones that affect insulin sensitivity.”
    5. What are the long-term lifestyle changes recommended after bariatric surgery?
      • “Long-term changes include a balanced diet low in calories and sugars, regular physical activity, and ongoing medical monitoring to ensure sustained health.”

    Research Papers/Citations

    Fenske, W., Athanasiou, T., Harling, L., Drechsler, C., Darzi, A., & Ashrafian, H. (2013). Obesity-related cardiorenal disease: the benefits of bariatric surgery. Nature Reviews Nephrology, 9, 539-551.

    Tu, J., Wang, Y., Jin, L., & Huang, W. (2022). Bile acids, gut microbiota and metabolic surgery. Frontiers in Endocrinology, 13.

    Gralka, E., Luchinat, C., Tenori, L., Ernst, B., Thurnheer, M., & Schultes, B. (2015). Metabolomic fingerprint of severe obesity is dynamically affected by bariatric surgery in a procedure-dependent manner.. The American journal of clinical nutrition, 102 6, 1313-22 .

    Related Reads

    Hear it From Others


    As one of the leading weight loss surgeons in Canada, Dr Gmora has gained a reputation for being a master of his surgical craft and producing outstanding weight loss results.