Why Hanbang Diet Differs from Simple Appetite Suppression

The number on the scale has been stuck in the same place for days. You've definitely cut down on how much you eat. But after eight in the evening, hunger becomes more distinct than before, and thoughts of food don't leave you even when you lie down to sleep. If you type your situation into a search engine, the word "willpower" is often the first to appear.

This state is not well explained by a problem of willpower. When weight decreases, the body simultaneously moves to reverse it through various pathways. Hormones that regulate appetite change, the amount of energy used during rest decreases, and body composition, including muscle, also changes. It's difficult to counter this entire process by only suppressing appetite. The point Korean medicine refers to when it says 'we look at the body type' is ultimately close to this.

Hunger Increases After Weight Loss

While it might seem that appetite would decrease with weight loss, measured results show the opposite. 「Long-Term Persistence of Hormonal Adaptations to Weight Loss」, a study by researchers at the University of Melbourne, Australia, published in the 『뉴잉글랜드 의학저널』 (New England Journal of Medicine) in 2011, tracked hormones in 50 overweight or obese adults without diabetes after prescribing a very-low-calorie diet for 10 weeks.

When an average of 13.5 kg was lost, satiety signals like leptin, peptide YY, cholecystokinin, and insulin decreased, while hunger signals like ghrelin increased, and subjective appetite also significantly rose. The problem lies in what followed. Even at 62 weeks, one year after the initial weight loss, levels of leptin, ghrelin, and peptide YY had not returned to pre-loss levels, and hunger also remained elevated. The researchers concluded that changes in appetite-mediating substances that promote weight regain do not revert to their original levels.

This is why an appetite-suppression-focused approach becomes difficult. While signals can be overridden from above with medication or willpower, the conditions that generate those signals themselves remain.

Metabolism Decreases to Match Reduced Weight

The second axis is energy expenditure. A follow-up study published in the journal 『Obesity』 in 2016 by researchers at the U.S. National Institutes of Health (NIH) tracked 14 out of 16 participants in a weight loss competition program for 6 years. At the end of the 30-week competition, the average weight loss was 58.3 kg, and resting metabolic rate was 610 kcal lower per day.

Six years later, participants regained an average of 41.0 kg, a significant portion of the weight they had lost. However, their resting metabolic rate remained 704 kcal lower per day than baseline. The unexplained portion after adjusting for changes in body composition and age, known as metabolic adaptation, was -499 kcal per day. This means that even though weight returned, metabolism did not follow.

Compounding this is the issue of muscle. When calories are drastically reduced, not only fat but also lean mass decreases. When muscle decreases, the basal metabolic rate lowers further, and a lowered metabolism makes subsequent weight loss more difficult. It's a structure where the starting line is pushed back further with each repeated attempt at starvation.

There Are Studies Documenting What Happens After Discontinuing Medication

GLP-1 receptor agonists work by slowing gastric emptying and enhancing satiety signals. The STEP 1 trial, a representative clinical study of this class, was conducted for 68 weeks on 1,961 adults with a BMI of 30 or higher (or 27 or higher with weight-related comorbidities).

What is noteworthy is the extended observation that followed. An extended analysis of STEP 1, published in 『Diabetes, Obesity and Metabolism』 in 2022, tracked 327 participants who completed 68 weeks for another year after discontinuing the medication. Up to 68 weeks, the average weight change was -17.3% for the experimental group and -2.0% for the placebo group. At 120 weeks, 52 weeks after discontinuation, the experimental group regained 11.6 percentage points, remaining at -5.6% compared to baseline. Cardiometabolic indicators such as blood pressure and lipids also mostly reverted towards baseline. The authors wrote that these results confirm the chronic disease nature of obesity and suggest that treatment must be continued to maintain improvements.

The way the 대한비만학회 (Korean Society for the Study of Obesity) 「비만 진료지침 2022」 (Obesity Treatment Guidelines 2022) defines pharmacotherapy is in the same context. The guidelines recommend considering pharmacotherapy for individuals with a BMI of 25 or higher who have failed to lose weight with non-pharmacological treatments, and to change or discontinue the medication if there is no more than 5% weight loss within 3 months of maintenance dose administration. The primary goal is 5-10% within 6 months. The premise that medication itself is not an endpoint but a tool accompanied by evaluation and adjustment is already embedded within the guidelines.

Appetite Suppressants Have Prescribed Durations

Psychotropic appetite suppressants have a different nature. In August 2020, the 식품의약품안전처 (Ministry of Food and Drug Safety) established the 「의료용 마약류 식욕억제제 안전사용 기준」 (Safety Use Standards for Medical Narcotics Appetite Suppressants), outlining the principles for the use of phentermine, phendimetrazine, diethylpropion, and mazindol. The target population is, in principle, BMI 30 or higher, or 27 or higher with risk factors. Administration is primarily short-term prescription within 4 weeks and should not exceed 3 months. More than two types should not be used together, they should not be used for children and adolescents, and they are not for cosmetic purposes.

The reason for setting an upper limit on the duration is due to dependence, tolerance, and psychiatric adverse reactions such as insomnia and anxiety. The fact that the Ministry of Food and Drug Safety operates a pre-alert procedure to monitor prescription history and notify of prescriptions that deviate from the standards is because cases of extending the duration by moving between multiple medical institutions have been identified.

'Looking at the Body Type' Means Classifying Types

Korean medicine does not view the same obesity as a single condition but divides it by pattern identification (辨證). The Korean Society for the Study of Obesity's explanation of pathogenic mechanisms presents pathways where qi deficiency (氣虛) weakens the transportation and transformation function, secondarily leading to phlegm-dampness (痰濕); pathways where overeating rich, sweet, and fatty foods (肥甘厚味) disrupts the spleen and stomach's transportation and transformation function; and pathways where internal damage from the seven emotions (內傷七情) affects organ functions. Those who eat well and have clear heat sensations and constipation (excess pattern type) and those who don't eat much but swell easily and feel fatigued (deficiency pattern type) are considered different conditions in Korean medicine.

This classification is not an abstract impression but a set of interview items. A re-evaluation study of obesity pattern identification questionnaires, published in the 『한방비만학회지』 (Journal of Korean Medicine for Obesity Research) in 2021, analyzed 203 actual clinical records through data mining. Among the six types—Food Stagnation (食積), Liver Qi Stagnation (肝鬱), Yang Deficiency (陽虛), Spleen Qi Deficiency (脾虛), Phlegm-Dampness (痰飮), and Blood Stasis (瘀血)—three types, Liver Qi Stagnation (33%), Food Stagnation (27%), and Yang Deficiency (24%), accounted for 84% of the total, and 39 out of 52 questions, excluding 13, were grouped into these three clusters. The fact that the distribution by type was heavily skewed was reported as evidence that the tool needed revision.

It is also accurate to mention the limitations of the evidence. The 「비만 한의표준임상진료지침」 (Korean Medicine Standard Clinical Practice Guidelines for Obesity), published in 2024 under the auspices of the Korean Society for the Study of Obesity, applied the GRADE methodology. Indicating the strength of evidence with grades also means that recommendations with lower grades are included. Clinical studies of Hanbang medicine in the obesity field often have small sample sizes and short observation periods, so it is not yet at a stage where the effects of individual prescriptions can be definitively stated.

Therefore, the utility of pattern identification lies not in "what cures" but in "what to look at first." JAIMDANG's 공비환 (Gongbihwan) is also a Korean medicine prescription whose administration is determined through a Korean medical doctor's diagnosis and prescription, and it is an in-house prescription formulated according to the monarch-minister-assistant-envoy principle. Preparation is carried out at an off-site herbal dispensary in Paju, Gyeonggi Province, using standardized medicinal herbs, with indicator components quantified by HPLC, and self-inspections for heavy metals and residual pesticides, as well as batch-specific quality inspections, with traceability by lot number. Detailed processes are summarized in [Off-site Herbal Dispensary and Hanbang Medicine Quality](/en/journal/wonoe-tangjeon-quality), and precautions before taking are in [Precautions When Taking Diet Hanbang Medicine](/en/journal/diet-hanyak-precautions).

Four Things to Prepare Before Consultation

• List your weight loss attempts to date in chronological order — including methods, duration, and reasons for stopping. What failed is the starting point for the next plan.
• Record when hunger increases for a few days — note the time of day, time elapsed since your last meal, and previous day's sleep duration to reveal patterns.
• List any medications you have taken or are currently taking by ingredient name — including appetite suppressants, GLP-1 agonists, Hanbang medicine, and health functional foods, along with the duration of use. Product names alone do not reveal ingredient overlaps.
• Set your goals with both numbers and a timeframe — the primary goal suggested by the guidelines is 5-10% within 6 months. Goals without a timeframe cannot be evaluated.

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References

• Sumithran P. et al., Long-Term Persistence of Hormonal Adaptations to Weight Loss, *New England Journal of Medicine* 365:1597-1604, 2011
• Fothergill E. et al., Persistent metabolic adaptation 6 years after "The Biggest Loser" competition, *Obesity* 24(8):1612-1619, 2016
• Wilding J.P.H. et al., Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension, *Diabetes, Obesity and Metabolism* 24(8):1553-1564, 2022
• 대한비만학회 (Korean Society for the Study of Obesity), 「비만 진료지침 2022」 (Obesity Treatment Guidelines 2022) Summary (8th ed.)
• 식품의약품안전처 (Ministry of Food and Drug Safety), 「의료용 마약류 식욕억제제 안전사용 기준」 (Safety Use Standards for Medical Narcotics Appetite Suppressants) Established, 2020

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*This article was written to convey physiological mechanisms and regulatory information related to weight management and does not guarantee the diagnosis or treatment efficacy for specific diseases. Hanbang medicine, including 공비환 (Gongbihwan), is a prescription determined by a Korean medical doctor's diagnosis and prescription, and responses and outcomes may vary by individual. If you are taking any medications, please be sure to inform your consultant during the consultation.*