How much weight does a Korean diet take off?

People often say Korean food helps with dieting. Whether rice, soup, seasoned vegetables, and kimchi make a slimming menu depends on how much is eaten. One study kept the amount similar and changed only the menu.

What the study looked at

In 2022, Min Jung Kim and colleagues sent meals to 52 women with obesity and had them eat those meals. They were 30 to 50 years old, mean 38.7. Their body-size score was at least 25 and under 30. That score is called BMI: weight in kilograms divided by height in meters squared. In Korea, 25 or more is treated as obesity. Mean weight at the start was about 65 kg, and the mean score was 25.4 to 25.5.

One month was a traditional Korean menu: mixed-grain rice, soup, kimchi, seasoned vegetables, and fish or a small amount of meat. The other month had more meat, bread, noodles, salad, and stir-fried or deep-fried dishes. White rice was more common on that menu too. After one month they waited 4 weeks, then switched. The pause was there so the first menu would not still be affecting the next month.

The meals were delivered to their homes. The women sent photos before and after eating, and leftovers were subtracted from those photos. The study is registered as KCT0005340.

Daily calories were almost the same. The Korean menu was 1,834 kcal. The comparison menu was 1,859 kcal. The spread between people was 106 and 60.5. The gap between menus was small enough to be chance (p = 0.14). The paper says these women were eating about 2,200 kcal a day before the study. The researchers’ target for daily needs was 1,900 kcal.

The food itself differed. Whole grains, with the outer layer left on, were 197 g a day on the Korean menu and 1.7 g on the comparison menu. Vegetables were 395 g and 278 g, kimchi 171 g and 109 g, meat 12.9 g and 30.9 g. Fiber was 36.7 g and 21.3 g. The glycemic index says how fast the same amount of carbohydrate raises blood sugar, with glucose set at 100. The Korean menu was 50.3. The comparison menu was 68.1. Cholesterol in the food was 146 mg and 272 mg. Sodium was 3,573 mg and 3,632 mg, with no difference between menus (p = 0.11).

Results

The body-size score fell 0.76 on the Korean menu and 0.32 on the comparison menu. The spread was 0.58 and 0.43. Inside each menu, the before-and-after drop was real. Whether the Korean menu fell more was not clear in these 52 women (p = 0.12). Waist circumference fell 2.62 cm and 1.08 cm, and that menu gap was not clear either (p = 0.11). The share of body weight that was fat fell 1.12 and 0.88, with no menu gap (p = 0.46).

The blood test split. Total cholesterol fell 30.0 mg/dL on the Korean menu and 12.8 mg/dL on the comparison menu (p = 0.007). Triglycerides fell 26.4 mg/dL on the Korean menu, and before and after differed. The comparison menu’s 6.6 mg/dL was not a confirmed change. The comparison of the two menus was p = 0.018. Cholesterol left after removing HDL fell 21.1 mg/dL and 6.8 mg/dL (p = 0.044). HDL is the part often called the better cholesterol.

HDL itself fell 8.9 mg/dL on the Korean menu and 6.0 mg/dL on the comparison menu. Both menus were lower than at the start, and it was not clear which was lower (p = 0.069). Morning fasting blood sugar fell about 3.7 mg/dL on both, with no menu gap (p = 0.76).

A study that used American menus

In 2020, Seong-Ah Kim and colleagues had adults with overweight or obesity eat three menus for 4 weeks each: a Korean menu, a menu built from the 2010 U.S. dietary guidelines, and a menu common in the United States. They rested 2 weeks between menus. Fifty-four of 61 people finished. The study is registered as KCT0002437.

The paper’s summary says the Korean menu lowered the body-size score, the share of body fat, total cholesterol, and LDL cholesterol more than the other two menus. LDL is the cholesterol treated as the one more likely to build up in blood vessels. Every statistical comparison of the menus was p < 0.05. During the Korean-menu weeks, HDL fell (p = 0.001) and fasting blood sugar rose (p = 0.018). On the American menu and the guidelines menu, HDL rose and fasting blood sugar stayed put. The summary does not say how many kilograms of body weight were lost.

Limits

The 2022 study included only women with obesity, each menu lasted 4 weeks, and the food was delivered. These numbers do not carry over as they are to men, to someone already lean, or to spicy pork and fried chicken ordered at a restaurant.

The weight drop sits closer to eating fewer calories than usual than to the name of the menu. The researchers also write that both groups ate less than usual, and that this is why weight fell. The 0.76 drop on the Korean menu is not the gap versus the comparison menu. The comparison menu also fell, by 0.32.

The rice in this Korean menu was 197 g of whole grain a day. Sodium, the number used for how salty the food was, was about 3,600 mg a day on both menus. The researchers say that is above the amount the Korean nutrient standard treats as enough. HDL fell on the Korean menu too. The cholesterol numbers did not all move in a welcome direction.

The 2020 weight result is known only as far as the statistics in the summary. The rise in fasting blood sugar while eating the Korean menu in that study, and the drop of about 3.7 mg/dL on both menus in 2022, are different results.

What this means for a log

What moved weight in this study was the lower calorie intake, plus mixed grains, vegetables, and fiber, ahead of the label “Korean food.” If a photo misses the rice, the broth, or the oil, a 1,834 kcal table and a larger one land as the same record. The salty side shows up only when the kimchi and the soup are visible. Writing a lower calorie number because the meal is Korean food parts ways with this study.