– These drugs provide very effective support for patients with type 2 diabetes and obesity, but they are not “slimming drugs” and should not be used by people who want to lose a few pounds,” says Prof. Ph.D. n. med. Lucyna Ostrowska, internist and specialist in clinical dietetics, head of the Department of Dietetics and Clinical Nutrition at the Medical University of Białystok and the Center for the Treatment of Obesity and Diet-Related Diseases in Białystok.
Slimming injections
Liraglutide, semaglutide and dulaglutide were developed for patients with type 2 diabetes. These drugs mimic the action of one of the gut hormones secreted by the body after a meal. Taking them increases the production of insulin, which transports sugar from the blood into the body’s cells, and reduces the production of glucagon, which in turn releases sugar from the liver into the bloodstream. This results in the regulation of blood glucose levels after a meal.
An obese patient with impaired functioning of the hunger center cannot lose weight because he cannot control how much he eats.
During clinical trials, it was found that GLP-1 analogues stimulate the satiety center and inhibit the hunger and appetite (reward) centers. They also slow down stomach emptying, which stimulates the vagus nerve, which sends information to the satiety center in the hypothalamus, thereby reducing the feeling of hunger. Drug manufacturers quickly determined that slightly higher doses were needed to reduce adipose tissue and restore adequate cytokine secretion than to treat type 2 diabetes. Preparations for the treatment of obesity appeared on the market.
However, experts have doubts whether GLP-1 analogues alone will solve the problem of obesity. – Undoubtedly, GLP-1 analogues reduce adipose tissue, especially visceral fat, reduce its inflammation, thus providing an opportunity to reverse metabolic disorders such as insulin resistance, prediabetes or hypertension, as well as to effectively treat type 2 diabetes – says Prof. Ostrowska. They also reduce the risk of cardiovascular diseases such as heart attack or stroke, which can be complications of obesity. However, they do not guarantee a lasting effect, especially if they are discontinued too quickly.
Stopping the drug unblocks the feeling of hunger and satiety problems. – If the patient returns to the pre-treatment diet, it is expected that he will gain weight quickly and his metabolic problems will come back like a boomerang. To prevent this from happening, the treatment must be long-term and, at the appropriate time, the dose must be gradually reduced, constantly working on improving eating habits and increasing physical activity. Without this, the effects of the treatment will not be maintained – warns Prof. Ostrowska.
Exercise not only burns off excess calories from food, but also increases your resting metabolic rate, which means your body uses more energy for breathing, digestion and excretion.
Stress or hormonal disorders
What happens to the body of a healthy person who takes weight-loss injections? – It is difficult to say because the clinical trials did not include patients with a BMI below 27 kg/m2 – says Prof. Ostrowska. For her, overweight people should not use these medications, as excess weight is not an indication for their use. The exception are patients who, despite a normal BMI, develop metabolic disorders such as hypertension, reduced HDL (“good” cholesterol), increased triglycerides or pre-diabetes. These are thin people who tend to accumulate abdominal fat, which causes metabolic disorders, as in people who are obese.
– I advise people who suddenly gain a few pounds to first look for the cause of the problem and undergo check-ups – says Dr. n. med. Anna Jeznach-Steinhagen, internist, diabetologist, assistant professor at the Department of Clinical Dietetics at the Medical University of Warsaw. It may be that the reason for weight gain is hormonal disorders, for example, related to menopause, hypothyroidism or polycystic ovary syndrome. Or maybe it is caused by a stressful period in life, which provokes eating emotions. – Slimming injections will not solve these problems. They need to be treated differently, emphasizes Dr. Jeznach-Steinhagen.
Contrary to popular belief, weight loss injections are not intended to treat insulin resistance. This is a condition in which muscle and liver cells cannot metabolize glucose because they are already overloaded with energy stores. They stop responding to insulin, which allows glucose to be metabolized. The body tries to force them to do this by secreting more insulin, but high levels of insulin in the blood stimulate appetite and block the breakdown of fat tissue. Therefore, with insulin resistance, it is difficult to lose weight.
In some patients, insulin levels increase under the influence of the drug, and with it, appetite. Theoretically, the desire to eat should be suppressed by a GLP-1 analogue, provided that the patient uses it in the correct dosage. And this is not always the case, because prescriptions for these drugs are often written by random doctors who have no experience in their use. If the dosage is incorrect, the weight loss effect may be weak or may not occur at all. There is also suspicion that trying injections for weight loss may increase insulin resistance in people who have already had problems with it.
The concern that GLP-1 analogues may increase insulin resistance in slightly overweight people is not shared by Prof. Ostrowska. – These drugs will only increase insulin secretion when the post-meal glucose concentration is very high, which means that the patient already has metabolic disorders and therefore qualifies for treatment with these drugs – says Prof. Ostrowska. – Furthermore, clinical trials confirm that these drugs improve insulin sensitivity of muscle tissue, adipose tissue and liver cells, including in patients with obesity, polycystic ovary syndrome or non-alcoholic fatty liver disease. Although this has not been tested in overweight people, the drug probably works the same way for them – adds Prof. Ostrowska.
– Thanks to GLP-1 analogues, most overweight patients without metabolic complications will probably lose several kilos within 8 to 12 weeks – says Dr. Jeznach-Steinhagen. Faster than with a good weight loss diet, but unfortunately not healthier. – The faster the patient loses weight, the greater the loss of muscle mass, which results in a reduction in the resting metabolic rate, i.e. the energy the body needs to live – warns Dr. Jeznach-Steinhagen. As a result, the patient, eating the same foods, will have a greater tendency to gain weight. Each time he causes his basal metabolic rate to decrease in this way, it will be more difficult for him to maintain the weight. This is why people who constantly follow weight loss diets or fasting have difficulty losing weight.
Dose control
A very important issue when using GLP-1 analogues is to skillfully increase the dose. – If this is done too quickly, the patient actually stops eating. Eat some yogurt and a few lettuce leaves, says Dr. Jeznach-Steinhagen. You quickly lose excess weight, which causes euphoria, but in the long term it can lead to nutritional deficiencies. After some time, your hair begins to fall out, your nails begin to break, and your skin condition worsens. The skin loses its firmness, facial features become sharper, and wrinkles become more visible.
– A highly restrictive diet can contribute to complications such as heart rhythm disturbances, gallstones or their complication in the form of pancreatitis – says Prof. Ostrowska. Manufacturers of GLP-1 analogues warn about these risks in leaflets, but patients apparently do not care. Doctors point out that patients who are obese due to this disease are more prone to cholelithiasis and pancreatitis than those with normal body weight, and a restrictive diet can further intensify the tendency to these disorders. It promotes the retention of bile in the gallbladder and the formation of deposits, which form stones.
Obesity itself significantly increases the risk of pancreatitis also through excessive concentrations of free fatty acids and triglycerides in the blood, but taking the drug itself does not cause this. – If this were the case, it would be noted in clinical trials – explains Prof. Ostrowska. However, he urges caution. – For my obese patients taking GLP-1 analogues, I order abdominal ultrasound and blood tests to check the concentration of pancreatic and liver enzymes – says Prof. Ostrowska. It is not known whether overweight people should also take the risk of such complications into account. No research has been carried out on this subject.
Slightly overweight people who dream of losing weight without making sacrifices should first consider what they will do once they reach their dream weight. – When the weight plateaus, many people lose the motivation to spend several hundred zlotys a month on slimming injections, so they stop taking medication. They then feel very hungry and crave snacks, says Dr. Jeznach-Steinhagen. People who tend to snack will quickly return to their pre-therapy weight or even gain a few pounds.
– This can be avoided by changing eating habits and increasing physical activity. However, most people use these medications to avoid counting calories and sweating during exercise, says Dr. Jeznach-Steinhagen. – Many patients realize that stopping the medication without changing their lifestyle will mean going back to the way things were before, which is why they are determined to continue taking the medication and are afraid to get another pack.
You can’t do this without a nutritionist
– If an overweight patient has changed his or her eating habits while taking the drug and is able to maintain them for the rest of his or her life, the adventure with GLP-1 analogues is likely to be beneficial for his or her health. Otherwise, they should not be stopped suddenly, says Dr. Jeznach-Steinhagen. The discontinuation should last at least several weeks, twice as long as the dose increase at the beginning of therapy.
– Slightly overweight patients often ask me about the point of taking GLP-1 analogues – admits Dr. Olga Paluchowska, clinical nutritionist. – I calm their enthusiasm by explaining that they do not need these drugs, because if they follow a nutritional plan tailored to their needs, they will lose weight without the help of drugs. In addition, by losing weight with a nutritional plan, the patient will not be exposed to the side effects of drugs and the risk of increasing insulin resistance.
An obese patient with impaired functioning of the hunger center does not know the feeling of satiety. He cannot lose weight because he does not control how much he eats, when he should stop, or the difference between his appetite for something specific and his hunger. Therefore, most obese patients need both medications, such as GLP-1 analogues, as well as a nutritionist and often also a psychologist. – Perhaps disturbances in the sensation of hunger and satiety begin earlier in some people, already in the phase of overweight – notes Prof. Ostrowska. This would justify treatment with GLP-1 analogues in overweight patients as well. However, further research is needed to determine this.
