Unveiling the truth behind weight loss products with no side effects: A scientific analysis of everything from enzymes and carnitine to sauna baths.

No dieting, no side effects, absolutely effective weight loss methods: I. Are weight loss products really magical? Many people believe that there must be some magical method in the world that allows us to easily and healthily solve the problem of obesity without experiencing the pain of hunger. Therefore, weight loss products or weight loss stores that use "no side effects, no dieting" as their selling point always attract a large number of followers. However, what is the weight loss mechanism of these methods? Are they really as magical as the merchants claim? Let's explore them one by one. The most popular weight loss products that do not require dieting are enzymes. "Enzyme" is originally a Japanese word, which is the same as the Chinese word "enzyme". However, enzyme products are not completely equivalent to enzymes. Some merchants just use the concept of "enzyme" to call a mixture of fruits and vegetables fermented by microorganisms "enzymes". Someone on the Internet conducted an experiment on the hydrolysis of starch by enzymes, and claimed that the enzymes extracted from fruits and vegetables can break down sugars and fats in the body, and can also promote the elimination of accumulated waste in the body, so as to lose weight and beautify the skin, without dieting, easy weight loss, and no side effects. In fact, enzymes in living organisms can indeed break down energy-producing nutrients such as carbohydrates, fats, and proteins absorbed in the intestines. However, this breakdown only occurs when there is direct chemical contact with these substances and a suitable internal environment. The enzymes in enzyme products are often polysaccharides, whose biological activity decreases after entering the human digestive tract. They are hydrolyzed and ultimately absorbed by the body, without ever having a chance to exert their function. As for the laxative effect of enzyme products, this may be due to the addition of substances like fructooligosaccharides and xylooligosaccharides that promote the growth of beneficial intestinal bacteria. Excessive consumption can even cause diarrhea. L-carnitine is a key substance in fat metabolism, acting as a carrier for fat transport, delivering long-chain fatty acids to the mitochondria for oxidative breakdown. L-carnitine was originally used as a nutritional supplement for athletes to enhance energy production and improve endurance during exercise. However, in recent years, some weight-loss products have added L-carnitine, claiming that this increases the concentration of L-carnitine in muscles, thereby enhancing fat oxidation. However, existing research shows that the amount of L-carnitine synthesized in a normal adult body is sufficient for its use, and there is no need to worry about deficiency. Furthermore, simply taking L-carnitine orally does not change the concentration of L-carnitine in muscles. In addition, fat oxidation does not solely rely on L-carnitine carriers for transport; it also requires the participation of various enzymes and other substances. Therefore, it is impossible to achieve weight loss by ingesting L-carnitine. Besides L-carnitine, many oral weight-loss products on the market contain various ingredients such as caffeine, catechins, spirulina, cassia seeds, and lotus leaves. Most of these ingredients claiming to reduce fat lack scientific evidence. A few, such as caffeine and green tea, do have some properties that can promote fat metabolism; however, their effects are minimal. It is important to note that some weight-loss products may add prohibited drugs to appear effective. These illegally added ingredients are not listed, and their dosage is unknown. Long-term use of such products can seriously damage consumers' health and may even threaten their lives. Meal replacements, as the name suggests, are foods that replace part or all of a regular meal. Meal replacement products are generally high in fiber, low in calories, and provide a sustained feeling of fullness, which is why some businesses market them as weight-loss foods. However, the claim that these meal replacement products can lead to weight loss without dieting or side effects is nonsense. Consuming meal replacement products between meals will not only fail to help you lose weight but will actually lead to weight gain due to increased calorie intake. Weight loss will only occur if the calories from the meal replacement product are lower than your daily energy expenditure. Furthermore, most meal replacement products currently on the market are not nutritionally balanced, and relying solely on meal replacement products for all three meals can easily lead to malnutrition and a range of health problems. Moreover, replacing regular meals with meal replacement products is itself a form of restricting the types and amounts of food consumed-essentially "dieting"-so how can you claim "no dieting is needed"? However, for patients diagnosed by a doctor as overweight or obese, using legitimate meal replacement products to replace part of their regular meals and reduce total calorie intake can indeed help with weight loss. This is contingent on a balanced diet of regular meals and meal replacement products, and should be done under the scientific guidance of a nutritionist. Besides edible weight loss products, some topical physical weight loss methods are currently booming. However, compression stockings that claim to "slim legs" actually have no fat-burning effect; they merely compress muscles and reduce water retention, making your leg circumference appear slightly smaller. Slimming creams containing various weight-loss ingredients often result in weight loss after application and massage, mostly due to dehydration. As for acupuncture, thread embedding, cupping, and other methods utilizing traditional Chinese medicine's meridian theory for weight loss, current clinical evidence is insufficient, and most require combined with controlled diet and exercise to be effective. Furthermore, while liposuction can remove fat, weight regain is likely after surgery if dietary restrictions are not maintained. Liposuction also carries certain risks, potentially leading to skin laxity, hematoma, infection, and even serious complications such as fat embolism. Theoretically, any substance that can produce additional effects on the body (i.e., "efficacy") has the potential for side effects, whether ingested or applied topically; there is no absolute safety. Therefore, claims of "no side effects" and "absolute effectiveness" are both exaggerated assertions. In short, we should be cautious about commercial products that promise "no side effects, no dieting required" for weight loss. II. The Essence of Weight Loss Obese patients are generally characterized by an increase in the volume and number of fat cells, an abnormally high percentage of body fat (body fat percentage), and excessive fat deposition in certain areas. Therefore, weight loss is not about reducing water, muscle, or bone mass; what we need to reduce is the percentage of body fat. The first law of thermodynamics tells us that energy cannot be created or destroyed; it can only be transformed from one form to another, while the total energy remains constant. When energy intake exceeds energy expenditure, the excess energy is converted into fat and stored in the body. To lose weight, energy expenditure must exceed intake, i.e., by controlling diet to reduce energy intake and increasing energy expenditure through exercise. III. No Side Effects, No Dieting Required, Scientific Weight Loss Successful weight loss involves two distinct stages: achieving weight loss and maintaining body shape. Therefore, weight loss is a lifelong commitment. Scientific weight loss should be a process of reshaping healthy lifestyle habits: a balanced diet, changing dietary structure and portion sizes to reduce fat and calories; increased physical activity and exercise, choosing sports you enjoy and cultivating exercise habits; counseling is also important, as nutritionists or counselors can professionally guide people to avoid easily giving up on their weight loss plans. While this type of weight loss is slow, it is stable and sustainable because it does not harm health and does not require dieting. Sauna Weight Loss Method: I. What is the Sauna Weight Loss Method? The word "Sauna" is Finnish, originally meaning "windowless wooden house," referring to the process of using steam to treat the body in a closed room. Traditional Finnish saunas generate steam by splashing water onto heated stones in an enclosed room. This method, which creates high temperatures (80-100℃) and low humidity (5%-70℃, with humidity near saturation), is called a steam bath. These two types of steam baths constitute the main body of sauna bathing in my country. Due to research showing multiple health benefits, it has gradually gained acceptance and become a fashionable and healthy leisure activity. At some point, the claim that "sauna baths help with weight loss" spread in weight-loss circles, attracting weight-loss enthusiasts eager to try it. This claim is not unfounded. Multiple studies and practices have proven the weight-loss effects of sauna baths. A study based on... Studies on sedentary young men and women have found that a single sauna bath can lead to weight loss; a study on obese men indicated that sauna baths reduced their weight. Furthermore, some athletes choose sauna baths to help them lose weight before competitions. II. The Truth About Sauna Baths for Weight Loss Whether dry or wet, sauna baths are essentially a form of high-temperature therapy. As the ambient temperature rises, so does the body temperature. To increase heat dissipation and restore body temperature to normal, the thermoregulatory center releases signals to promote sweat gland secretion. Studies show that the rate of sweating in a sauna is approximately 0.6-1.0 kg/h, with an average sweat volume of 0.5 kg during a 15-30 minute sauna session. Another experiment found that six consecutive 15-minute sauna baths resulted in a 2.3% weight loss for the subjects, while if the subjects drank the same amount of water as the weight lost in the previous sauna bath during the rest intervals between baths, the result was only a 0% weight loss.Saunas reduce body weight by 4%. Therefore, the main reason saunas can help with weight loss is the loss of body fluids. In addition, the high temperature excites the sympathetic nervous system, causing an increased heart rate and blood pressure, leading to increased resting energy expenditure – another mechanism for sauna weight loss. However, the energy expenditure in this way is only slightly higher than that of sitting still. Expecting to increase energy expenditure through a few tens of minutes of sauna bathing daily for weight loss is unrealistic. Moreover, improper sauna bathing can lead to health risks such as dehydration and burns; special populations, such as those with severe aortic stenosis or unstable angina, may experience myocardial ischemia after sauna bathing; and patients with orthostatic hypotension may experience fainting due to a drop in blood pressure after sauna bathing. Therefore, sauna bathing not only fails to achieve weight loss but can also be detrimental to health in some cases. III. Passive exercises such as soaking and massage can also consume body energy. The reason sauna bathing has secured a place in the weight loss market is by exploiting people's inertia and lack of exercise. A major factor contributing to obesity and overweight is a lack of physical activity, and being overweight and obese exacerbates laziness, making people even less willing to exercise. The desire to burn energy despite a dislike for exercise has led to the emergence of various so-called "passive exercise weight loss methods" such as bathing, massage, and fat-burning machines. But are these "passive exercise weight loss methods," which rely solely on external force to assist in exercise, truly as effective as advertised? An adult's energy expenditure is primarily composed of three factors: basal metabolism, physical activity, and the thermic effect of food. Physical activity accounts for 15% to 30% of total energy expenditure and is a key component in controlling overall energy consumption. During active physical activity, skeletal muscles contract forcefully, significantly increasing energy expenditure compared to a resting state. At this time, the body mobilizes the breakdown of carbohydrates, proteins, and fats to provide energy for skeletal muscle contraction. Passive exercise, however, relies on external force to activate body tissues; the skeletal muscles do not contract forcefully. Therefore, passive exercise does not increase energy expenditure. To lose weight by increasing energy expenditure, it is essential to choose exercises that actively generate energy through muscle work, ideally low- to moderate-intensity aerobic exercise, which can be sustained for a longer period and primarily relies on burning fat for energy.