"I Don't Even Want to Pick Up My Spoon"... Appetite Loss Arrived Like Morning Sickness [Maunjaero Report] ②

93kg Reporter’s Maunja Experience (Weeks 2?3)
"Can't Eat Anymore"
Why Just Seeing Food Kills My Appetite
A Diet Method That Changes Your Metabolism

Editor's NoteThe path to treating obesity, once a major challenge in the medical field, is opening up thanks to the advent of GLP-1 (glucagon-like peptide-1) class medications, which influence satiety and appetite suppression. Recently launched in Korea, Maunjaero is a dual agonist of GIP (glucose-dependent insulinotropic polypeptide) and GLP-1, demonstrating higher weight loss efficacy and evolving as a treatment for complex metabolic diseases such as diabetes and MASH (metabolic dysfunction-associated steatohepatitis) compared to previous medications. However, caution is needed against the social trend of abusing these drugs for mere cosmetic purposes or mistaking them as a 'miracle weight loss injection.' This series is planned as a total of six installments (over 12 weeks), documenting the experiences of a journalist diagnosed with severe obesity, including the treatment process, effects, side effects, and lifestyle changes, with the aim of promoting proper use of obesity medications and a healthy life. Not everyone will experience the same effects of Maunjaero as the journalist did. Readers considering the use of obesity medications, which may involve side effects, should always consult a physician.

Chickpea bibimbap, a favorite during the diet period. Mixed half a bowl of brown rice, chickpeas, chicken breast, vegetables, and low-sugar gochujang. (First photo) After the second week on Maunja, appetite decreased so much that a lot of brown rice was left uneaten. (Second photo) Chickpeas, rich in dietary fiber and protein, were consumed frequently during the diet. Even when eating white rice, only 3 to 4 spoonfuls of white rice were eaten with a generous amount of chickpeas on top. This eating method was to maintain the meal order of dietary fiber → protein → fat → carbohydrates. (Third photo)

"Ah, I really can't eat anymore..."

At 4 p.m. on September 14, I received my second Maunjaero injection. A couple of hours later, as I tried to have dinner, these words, which I had never uttered in my life, slipped out unconsciously. I couldn't even finish half of my bibimbap made with brown rice, chickpeas, vegetables, and chicken breast. In the first week of treatment, I had no trouble eating the entire portion. The queasy feeling was several times stronger than after the first injection. My appetite vanished, and I found myself lowering my spoon without realizing it. Since I still needed to get enough protein, I picked out the chickpeas, chicken breast, and bean sprouts and forced myself to eat them.

Loss of appetite even before eating... How GLP-1 controls hunger

The appetite-suppressing effect of Maunjaero became noticeable in the second week. Satiety lasted much longer, and the amount of food I ate dropped significantly. By changing the order of eating to dietary fiber → protein → fat → carbohydrates, my carbohydrate intake decreased even further. Even with this reduced intake, I did not feel much hunger.

The key ingredient in Maunjaero, GLP-1 (glucagon-like peptide-1), is a natural hormone secreted in the stomach. It is not a hormone that directly regulates 'ghrelin,' which stimulates appetite, or 'leptin,' which signals satiety from fat cells. Nevertheless, many patients report feeling 'full before even eating' after GLP-1 administration, because GLP-1 indirectly recalibrates the entire metabolism in which these two hormones operate.

When GLP-1 slows gastric emptying, the stomach stays full for longer. The stomach increases ghrelin secretion to signal hunger when it is empty, but with GLP-1 keeping the stomach full, ghrelin secretion naturally decreases, dulling the sensation of hunger. The urge to eat itself becomes weaker. Park Kyungmin, director of Seongsu Melting Clinic and advisor for the "Maunjaero Report," explained, "GLP-1 stimulates the hypothalamic satiety center and suppresses the appetite center, curbing appetite at the central nervous system level first. By delaying gastric emptying (from the stomach to the small intestine), the stomach remains full longer, which slows the rise in ghrelin and ultimately weakens hunger signals."

Conversely, leptin, which is responsible for satiety, often does not function properly in people with obesity. GLP-1 increases leptin signal sensitivity in the hypothalamus, helping the 'you can stop eating now' signal to be transmitted more effectively. Dr. Park said, "Maunjaero does not directly increase leptin, but it reduces 'leptin resistance,' allowing the same level of leptin to send satiety signals more effectively." In other words, GLP-1 creates an environment where hunger signals are weakened and satiety signals are strengthened, realigning the entire appetite control system.

With these mechanisms combined, satiety increases even before taking the first bite of food. In fact, research shows that groups administered GLP-1 reported about 40% higher satiety indices than placebo groups even before seeing food. The sensation I experienced after the second week-feeling full just by looking at food-was a direct result of these physiological changes.

Multiple failed diets... This time, let's change the body's metabolism

The main focus when planning the "Maunjaero Report" series and my diet was 'metabolic regulation.' While I received Maunjaero injections, I considered them only a supplementary tool for weight loss treatment. Given the cost and potential side effects, I thought long-term use was inappropriate. Ultimately, to lose weight and keep it off, it is necessary to improve the metabolic state that causes continuous weight gain by adopting healthier eating and exercise habits. The goal was to enhance the effect of Maunjaero while also enabling weight loss without it.

The first step was changing my diet. I cut out refined carbohydrates such as white rice and bread. The alcohol I used to drink two or three times a week was almost completely eliminated after my daughter was born. By avoiding foods that rapidly spike blood sugar, I found my concentration improved during morning work hours, and I could easily fight off drowsiness without the coffee I used to rely on. As my metabolism improved, my body felt lighter and my mind clearer.

Maintaining stable blood sugar is key to weight loss. When blood sugar rises rapidly after a meal, excess insulin is secreted, converting leftover glucose into glycogen and fat. When blood sugar then drops quickly, strong hunger returns. Repeated 'blood sugar spikes' cause the body’s metabolism to shift toward storing energy rather than burning it. In contrast, reducing refined carbohydrates and increasing protein and dietary fiber slows the rise in blood sugar, stabilizes insulin secretion, and reduces fat accumulation. A blood sugar spike refers to the phenomenon where blood sugar soars and then plummets rapidly after a meal.

Dr. Park Kyungmin explained, "If you keep your blood sugar curve gentle, insulin is not excessively secreted, so the body receives fewer signals to 'store fat.' Maunjaero, by acting on both GLP-1 and GIP, suppresses post-meal blood sugar spikes and regulates insulin secretion, further enhancing the effects of these dietary changes."

Dietary adjustments were relatively smooth. The real challenge was exercise. With a five-month-old daughter to care for, it was not easy to find separate time for workouts. Instead, I chose to increase NEAT (non-exercise activity thermogenesis). After putting my baby to sleep, I would climb up and down the stairs of my 20-story apartment building five or six times, do squats while holding my baby, or sneak in push-ups while she slept. The goal was not a special exercise program but simply to increase movement in daily life.

Body composition changes were measured under similar conditions such as fasting in the morning before showering, but variations occur due to factors like body water content and fasting state. Even when using an InBody scale, it is said that it is more important to observe trends rather than daily values of key indicators such as weight, body fat mass, and skeletal muscle mass.

The scale reflected changes in weeks two and three of Maunjaero as well. My weight, which was 93.1 kg on September 7, dropped to the 91 kg range in the latter part of the second week, and reached 90.1 kg by the end of the third week-a loss of about 3 kg. Skeletal muscle mass decreased from 33.6 kg to 32.0 kg, and body fat mass dropped slightly from 33.8 kg to 33.5 kg.