Professor Dr. med. Dr. habil. Thomas Carus, FACS, is a leading figure in the world of surgery and medicine, particularly in the fields of abdominal surgery and minimally invasive procedures. His appointment as Chief of the Department of General and Visceral Surgery at Bassum Clinic marks a significant milestone that is attracting considerable attention not only in Lower Saxony but also beyond. With an impressive array of additional qualifications and extensive expertise, Prof. Dr. Carus is the ideal specialist for a wide range of conditions affecting the gastrointestinal tract, the thyroid, vascular diseases, and, in particular, obesity. His skills span the entire spectrum of abdominal surgery, and his achievements in minimally invasive surgery are outstanding.
The decision to take over as head of the department in Bassum was based not only on his own enthusiasm but also on the high level of expertise of the existing team and the clinic’s modern facilities. Prof. Dr. Carus is known for his precise, guideline-based treatment approaches, which are made possible by innovative techniques such as laparoscopic surgery. People in the region between Bremen and Osnabrück have traditionally placed their trust in the outstanding quality of care in Bassum, which was another incentive for Prof. Dr. Dr. Carus to commit to working there. His extensive team enables him to fully leverage his broad expertise. His additional training in various fields, such as sports medicine, proctology, and palliative care, rounds out his profile as an exceptionally versatile surgeon.
In addition to his clinical work, Prof. Dr. Carus is also known as the author of many scientific publications, and his textbook *Atlas of Laparoscopic Surgery* has received widespread international recognition. His commitment to interdisciplinary approaches and his skills in management and health economics make him an integral part of the high-quality care provided in Bassum and the surrounding hospitals of the Diepholz Hospital Network. His experience as chief physician at other renowned hospitals, as well as his ongoing focus on innovative treatment methods—such as those for obesity—promise a continuation of his pioneering work in Bassum.
The editorial team of the Leading Medicine Guide had the opportunity to speak with Prof. Dr. Carus about this condition.
Obesity is a complex and widespread health issue that is gaining importance worldwide. This condition, characterized by excessive body fat, goes beyond aesthetic appearance and has significant impacts on the health and well-being of those affected. From its underlying causes to treatment options and its effects on various aspects of life—obesity has become a topic of increasing medical, social, and scientific importance. The main causes of obesity are diverse and often result from a combination of factors.
“Obesity is actually a behavioral disorder and a dynamic process. It often begins in adolescence, and food intake increases slowly and continuously over the course of a person’s life—more calories are consumed than are burned. The reasons are varied. Of course, there are medical conditions and medications that affect weight, and genetic predisposition also plays a role. Often, psychological factors drive people toward increased calorie intake, such as problems at school or bullying. The way someone was raised (such as eating habits at home) also plays a significant role. “You can’t pinpoint a single cause for obesity; it’s multifactorial,” says Prof. Dr. Carus, describing the causes of obesity.
The causes of the rise in obesity are multifaceted and result from a combination of factors.
Certainly, affluence plays a role, as easier access to more nutrient-dense foods and a more comfortable lifestyle can contribute to it. But the reasons are more complex and also include other factors. The food industry undoubtedly plays an important role. “The availability of processed foods that are high in calories, sugar, saturated fats, and additives has increased; these foods often don’t cost much and are always available. These foods are often high in calories but low in nutrients, and their nutrient density has increased over the past 30 years. For example, a hamburger from well-known fast-food chains has more calories today than it used to. And if you look at the sugar content, it has also increased dramatically. For example, a popular Asian sweet-and-spicy sweet chili sauce consists of 50% sugar! That’s why, when I’m shopping at the supermarket, I always turn every product over to read the sugar content information. So if one variety of a product has 6% sugar and another has 12%, I naturally choose the one with 6%. High sugar consumption is also linked to the rise in type 2 diabetes among patients. The newly introduced Nutri-Score, which ranges from A to E, is helpful. “Here, it is recommended that overweight patients—but really everyone—stay within the A and B categories, or at most C,” explains Prof. Dr. Carus. Changes in eating habits and a lack of exercise lead to an imbalance between calorie intake and energy expenditure. The growing trend toward sedentary work and reduced physical activity in modern lifestyles also contributes to weight gain. “To lose weight, a calorie deficit of 800–1,000 kcal per day must be achieved—in combination with 5 sessions of 30 minutes of exercise per week.”
With regard to surgical procedures for treating obesity, there are various options that are used depending on the individual needs and health conditions of the patients.
The use of gastric bands in the treatment of obesity has declined in recent years due to a number of factors. Studies have shown that gastric bands are less effective than other bariatric procedures, such as gastric bypass or sleeve gastrectomy, and often do not result in sufficient weight loss. In addition, they can cause various complications. Long-term studies have shown that many patients with gastric bands regain weight after a few years, which may be due to stomach expansion or a decrease in the band’s effectiveness over time.
“The gastric band is completely ‘out.’ It is merely a mechanical constriction, like a funnel, and the stomach itself remains unaffected. If the patient then drinks high-calorie beverages such as cola, for example, they can gain as much weight as they want despite the gastric band. They would have to adhere to dietary guidelines involving small, regular, and healthy meals. Furthermore, a gastric band can cause mechanical problems and lead to serious complications such as gastric perforation. If the gastric band then has to be removed, the yo-yo effect is particularly pronounced, and the patient quickly returns to their original weight,” says Prof. Dr. Carus regarding the gastric band, which has fallen out of “fashion,” and moves on to today’s standard procedures:
“Sleeve gastrectomy and gastric bypass are the standard methods today, with a roughly 50:50 split worldwide. The decision is made on a case-by-case basis. On the one hand, the patient’s opinion, their life circumstances, and their compliance are key factors, and it also always depends on what the clinic offers. Here at our clinic in Bassum, we implement a multimodal treatment approach that includes a six-month preparatory phase with at least 3–4 appointments with an obesity specialist during medical consultations and regular nutritional counseling. During these six months, various goals must be achieved, and step by step, we determine whether surgery is even advisable and, if so, which procedure is best. These six months are also required by health insurance providers, who must approve the surgery. During these six months, the patient typically loses about 10–15 kilograms, and their medical indicators improve. If a dramatic improvement occurs and the patient loses a significant amount of weight on their own, the conservative approach can be continued. Personally, I find this timeframe to be absolutely reasonable. After all, we are dealing with a patient who has behavioral issues. That cannot simply be compensated for with surgery alone. We generally follow up with our patients for five years after the procedure—or longer if necessary—depending on the multidisciplinary care provided. And that’s how I explain it to my patients as well: that we then have a five-year journey ahead of us together. These patients typically come to me with multiple comorbidities such as hypertension, diabetes, osteoarthritis, and other conditions caused by obesity. It usually takes about 10 years for a severely overweight person to find their way to me. Sometimes this happens based on a recommendation from an orthopedic surgeon whom the patient visited for knee pain—a surgeon who might recommend a joint replacement but advises the patient to lose weight first.”
Gastric bypass: In this minimally invasive procedure, the stomach is drastically reduced in size and bypassed by connecting the new, smaller portion of the stomach directly to the small intestine. Approximately 120–150 cm of the small intestine is bypassed, preventing food from passing through that section. This reduces the amount of food that can be consumed and leads to reduced nutrient absorption. Gastric bypass has proven to be an effective method for long-term weight loss and may be considered for patients with severe obesity or certain comorbidities (insulin-dependent diabetes mellitus, reflux).
Sleeve gastrectomy: In this minimally invasive procedure, about three-quarters of the stomach is removed, creating a tube-shaped stomach. This reduces feelings of hunger and the amount of food that can be consumed. In addition to promoting a faster feeling of fullness, this procedure also reduces the levels of the appetite hormone ghrelin. This technique is suitable for all patients with morbid obesity.
The choice of procedure depends on various factors, including the severity of obesity, the patient’s medical history, and their individual preferences. A careful evaluation by a multidisciplinary team of physicians, surgeons, nutritionists, and psychologists is crucial for determining the most appropriate treatment option. Each procedure has its own advantages and disadvantages, as well as potential risks, which must be considered on an individual basis.
Preparation and support before and after weight-loss surgery for obesity play a crucial role in long-term success.
Before the procedure, a comprehensive assessment of the patient’s health status and lifestyle habits is essential. Nutritional counseling helps prepare the patient for the procedure and establish healthy habits. Additionally, psychological support is important for managing anxiety and setting realistic expectations. After surgery, ongoing medical follow-up is of great importance. Regular checkups monitor the healing process and identify potential problems early on. Sustained dietary adjustments after surgery are crucial for preventing nutritional deficiencies and providing the body with the right nutrients. Exercise also plays an important role: a personalized exercise plan supports weight loss and improves health.
Semaglutide is a promising active ingredient that has recently come into increasing focus in the treatment of obesity. As an incretin mimetic, semaglutide belongs to the class of GLP-1 receptor agonists and is already being used successfully to treat type 2 diabetes. It has now also shown the potential to significantly support weight loss in overweight and obese patients. “Semaglutide is a medication for people with diabetes, and yes, it is also used to treat patients with obesity. In this case, the medication must be taken once a month at an increasing dosage and costs patients approximately 300 euros per month in the long term. The problem is that this must essentially be continued for life, because if you stop, the effect wears off, and the yo-yo effect returns very quickly. Furthermore, taking the medication should always be combined with a lifestyle change that includes a consistent diet—which is why I’m not enthusiastic about the use of semaglutide. After all, if you make lasting behavioral changes and stick to a sensible diet, you actually no longer need the injection. In addition, semaglutide causes side effects such as nausea and diarrhea, and can increase the risk of gallstones or pancreatitis, as well as headaches or dizziness. I can’t think of a single patient right now who absolutely needs that. And we mustn’t forget: Life isn’t just about being able to eat and drink a lot, but about entirely different things like sports, exercise, leisure, and social life. Of course, the latter is often linked to eating and drinking, but that can certainly be done in a moderate and healthy way,” notes Prof. Dr. Carus critically, citing another positive example:
“I just had a patient with a starting weight of 200 kilos who now weighs 150 kilos thanks to exercise and a healthier diet, and he called me to tell me that he walked a total of 300,000 steps in January. So he managed over 10,000 steps a day and is totally motivated. And that’s the path you have to take—it’s about changing your own behavior. And this is where I come in to support my patients. Since I have a very large catchment area—from Hamburg, Bremen, and Lower Saxony all the way to the Emsland region—I’ve introduced online consultations. The multidisciplinary approach is crucial. The cardiologist, the diabetologist, the internist, and the nutritionist are always on board to keep an eye on things like high blood pressure, insulin levels, and a healthy diet.”
Nutrition plays a central role. Nutrition specialists help develop preoperative meal plans to prepare patients for surgery. They provide information about changes in eating habits after surgery and support patients in adapting to a new lifestyle to achieve successful weight loss. Exercise therapy is another integral component. Both not only support weight loss but also promote overall health and well-being.
Excess Weight Loss (EWL) – Loss of Excess Weight
EWL refers to the loss of excess weight in obese patients. “If you take an average man who should weigh 100 kilograms but actually weighs 180 kilograms, he will certainly lose about 30–50 kilograms in the first three to six months following gastric sleeve or gastric bypass surgery. That’s half of his excess weight gone. Then the weight loss slows down a bit, and after about a year, he would weigh about 110–120 kilograms. And during this time, I always monitor the patient’s progress. This is when questions often arise, such as, “Why has my weight loss stalled?” Even if the target weight isn’t quite reached, the positive effects on health are enormous. The benefits are obvious: Blood pressure usually drops to a healthy normal level, people with diabetes often no longer need insulin after losing weight, and there’s one important thing we mustn’t forget: With a body mass index (BMI) over 40, life expectancy is reduced by 10–15 years. “If the BMI can be reduced to 30 or lower, the patient effectively regains those 10–15 years of life,” explains Prof. Dr. Carus, further elaborating on the success rate at his clinic:
“We’re truly very successful here. This is due, among other things, to the fact that patients are always cared for by the same doctor throughout the entire process, starting from day one. This is important because, along the way, the patient opens up, has to discuss personal matters, and needs someone they can trust. We have three bariatric surgeons at my clinic in Bassum, all of whom personally care for ‘their’ patients.”
Limited or inadequate coverage of obesity treatment costs by health insurance companies can lead to a number of problems.
It is important for the healthcare system and health insurance companies to focus more on the prevention and treatment of obesity. Coverage for evidence-based treatments and preventive measures should be improved to provide patients with better access to effective therapies. In addition, comprehensive coverage of weight-loss therapies and lifestyle interventions could lower long-term healthcare costs by helping to reduce obesity-related complications such as diabetes, cardiovascular disease, or joint problems.
“Health insurance companies know exactly where the specialists for obesity patients are located—there are about 40 clinics in Germany. And when these facilities submit a request to the health insurance provider for approval of a sleeve gastrectomy or gastric bypass surgery, the providers already know that the request is well-founded. That’s why I rarely experience a rejection of an application, and I always prepare everything 100% for the health insurance providers. Only once all the necessary expert opinions are available do I compile everything and send the application to the health insurance provider for coverage,” says Prof. Dr. Carus regarding dealing with health insurance providers, and at this point we conclude the conversation.
Thank you very much, Professor Dr. Carus, for sharing your insights on obesity with us!
