Within-group differences in body fat and diabetes tell a lot about the diet and susceptibility of the diseases to that group. What the ethny does (or does not do) affects how high their body fat will be and whether or not they become diabetic. Since body fat levels are related to diabetes, then looking at both variables together should tell a lot about the diet and lifestyles of the ethnies studied. The ethnies I will look at are Chinese, Japanese, Filipinos, Koreans, Mongolians, and Filipinos.
The Chinese have high levels of body fat (Wang et al, 2004) but have a lower BMI yet higher level of body fat than whites (Wang et al, 1994). BMI correlates with body fat percentage in the Chinese, while BMI and body fat percentage were related to DM (diabetes mellitus). Though BMI has its limits in people ranging from 24 to 27.9 BMI (Wang et al, 2011). New findings have shown that obesity in China may be underestimated (Gangqiang et al, 2017). That Chinese males have higher levels of body fat than white males held even after adjusting for age and BMI (Wang et al, 2011). The reality is that body fat percentage and diabetes, along with other diseases like prostate cancer (PCa) are increasing at an alarming rate in China (Tomlinson, Deng, and Thomas, 2008), so what is the cause?
The cause is very simple: The introduction of the Western diet. As I have written in the past, wherever the Western diet goes, diseases of civilization follow in high numbers in populations that previously did not eat that type of food. One analysis of the Chinese diet (compared with the Meditteranean, Japanese, and American diets) showed that “the Chinese diet has been shifting away from the traditional diet toward high-fat, low-carbohydrate and low-fiber diets, and nutrients intakes in Chinese people have been changing even worse than those in American people” (Zhang et al, 2015).
One study showed differences in dietary expectations between Americans (in Honolulu, Hawaii, so probably ethnically mixed) and Chinese in Changsha Hunan, China (Banna et al, 2016). The Chinese students mentioned physical outcomes such as “ such as maintaining immunity and digestive health” while American students state that they “balanced food groups” and balanced consumption with exercise (implying you can outrun a bad diet when you can’t…) while also stating that physical activity should be essential. American students stated that they needed to avoid foods high in fat. In that same manner, one Chinese student said “”Eat smaller amounts of meat, fish and vegetarian alternatives, choosing lower fat options whenever possible.” Meat, specifically beef and pork, was often cited as a food that should be limited” (Banna et al, 2016). Both groups of students in both countries erroneously assume that high-fat diets are bad for you—on the contrary, it’s high carb low-fat diets that are bad, which lead to DM.
The number of obese Chinese has surpassed the US; China is on its way to top the world in childhood obesity; and the incidence of diabetes is exploding in China. All due to the introduction of a Western diet. Something else worth noting: All Asian ethnies—at the same BMI—have higher levels of body fat and central adiposity, a risk-factor for diabetes (Deurenberg, Deurenberg-Yap, and Guricci, 2002).
Everywhere the Western Diet goes, obesity, diabetes, and disease soon follow and Mongolia is no different. Otgontuya et al (2009) showed that 6 percent of their study population were underweight, while 50.7 percent were in the normal range, 32.8 percent were overweight and 10.5 percent were obese, with women being slightly more likely to be overweight and obese. Rural people were more likely to be overweight and obese than urban people. Men had significantly lower body fat percent levels than women (26 and 34 percent respectively), women in the lowest age group had the lowest body fat percentage.
Mongolians living in China had impaired fasting glucose (IFG); those who had diabetes and IFG were more likely to be overweight and have higher central adiposity (Zhang et al, 2009). Mongolians eat an estimated 2,525 kcal per day, along with a fat/kcal ratio of 33.7—1.3 times higher than the Japanese and this is associated with their lower mortality (Komatsu et al, 2008).
As with other Asian nations, Korea has the same problems. Hong et al (2011) showed that in Korean men, muscle mass decreases and body fat increases with age while for women fat mass and obesity increased with age. I particularly like this study since they assessed percent body fat (and other variables) with the DXA scan—one of the gold-standard of assessing body fat. Another Korean study showed that high birthweight leads to obesity and higher levels of body fat but not muscle mass (Kang et al, 2018), and with the advent of the Western diet in Asia, we can expect higher rates of obesity. (Note that this is an observational study and thusly causation is not certain, future studies will tease out causation and I bet the Western diet plays a role.) Another study even showed that eating frequency is related to obesity when diet quality is high, but not low in Korean adults (Kim, Yang, and Park, 2018).
There is one more risk-factor in regard to Korean obesity—study time after school is associated with habitual eating which leads to becoming overweight and obese. In this sample, Korean children who reported studying after school and eating when they were not hungry during studying were at increased risk for developing obesity in later years (Lee et al, 2018).
There is one interesting thing to note in regard to Koreans and diabetes, though: High leg fat mass, along with lower leg muscle mass, significantly lowered the risk for DM, while those who had lower leg body fat but higher leg muscle mass had a higher risk for developing diabetes (Choi et al, 2017). Shin, Hong, and Shin (2017) show that “… BAI is less useful than BMI and other adiposity indices, such as the WHtR, the WHR, and WC. These indices may be better candidates for clinical use and to evaluate metabolic syndrome risk factors.” One mouse study showed that the traditional Korean diet prevented obesity and ameliorated insulin resistance (Choi et al, 2017) which implies that a shift back to the traditional Korean diet for Koreans would show positive health benefits.
Japan is similar to China as regards body fat percentage and BMI. They have a culture of fat-shaming (do note that it does not work but in fact makes the problem worse due to biochemical stress) and when one of their peers becomes overweight, they begin to shame in hopes that they will lower their weight. Though, despite their culture of thinness, in Japan, diabetes is a “hidden scourge“. This is due to, again, the Western diet reaching Japanese shores.
Rice is a major food staple in Japan. Since rice is a carbohydrate, then it follows that, if eaten in large amounts, one who eats more rice than another would have a higher chance of becoming a diabetic. Rice intake is associated with the onset of diabetes in Japanese women, with a significant increase in diabetes if the woman ate more than 420 grams of rice (3 bowls) per day; the association was pronounced in women who were physically-inactive, and nonobese (Nanri et al, 2010). The same was seen in Chinese women (Villegas et al, 2007).
However, Nanri et al (2010) state that “The mechanism by which increased rice consumption increases risk of type 2 diabetes remains unclear. … the association between rice intake and type 2 diabetes risk remained significant even after adjustment for these food factors, which suggested an independent role of white rice in the pathogenesis of type 2 diabetes.” The cause is very simple: White rice, as Nanri et al note, is high on the glycemic index scale. If a food is high on the glycemic index scale, then it will spike one’s blood sugar high, which eventually would lead to DM. It’s also worth noting that a low-carb diet was associated with a decrease in diabetes, most likely due to a decrease in white rice consumption (Nanri et al, 2015).
The Japanese, in comparison to other Asian countries, have low levels of obesity, though the maladies they acquire are in-line with their diet and what they eat. However, some have noted the fact that Japanese diabetes rates are low. (Notwithstanding their hidden scourge.) This is easily explainable: The percent of carbohydrate intake is nowhere as important as the absolute amount of carbohydrate consumed. Though their diabetic population has increased to over 10 million recently. This is, of course, due to the introduction of the Western diet in Japan.
The last ethny I will discuss are Filipinos. Body-shaming is, as it is in other Asian countries, prevalent. At a fixed BMI, in spite of both groups living in similar conditions and eating a similar diet, “Malay and Thai boys had a significantly higher %BF than Filipino boys and Thai girls had a significantly higher %BF than Malay and Filipino girls” (Liu et al, 2011).
Choi et al (2013) showed that Filipino men living in California with DM were more likely to be overweight and obese, and Filipino men without DM were still more likely to be overweight and obese (even when adjusting for age and other lifestyle factors, Filipinos still had a higher chance of acquiring DM. Though Korean women had the highest rates of DM, followed by Filipinas.
Filipino and Korean emigrants to America had higher rates of weight gain than Chinese emigrants (Oakkert et al, 2015). This could be due to cultural values back home, which then obviously change when they emigrate to America. Furthermore, they find themselves in obesogenic environments (See Lake and Townshend,2006; Townshend and Lake, 2017). The cause is the difference in the built food environment; this is why Filipino men and women have high rates of DM and CVD (cardiovascular disease).
Further, in Filipinas, increased socioeconomic status, urban residence, fewer pregnancies and lactations and spending more time away from home is positively associated with weight gain. Though a high waist-to-hip ratio and being overweight and obese was independently related to hypertension in Filipinas (Adair, 2012). This study documented weight changes in a 16-year period in Filipina women as they moved higher up the SES ladder. Adair (2012) does note that obesity is increasing in lower-income households, too, but not as quickly when compared to more affluent households.
Comparing body fat percentages amongst Asian-American groups indicates that not all Asian-American populations are not equal in body fatness (Alpert and Thomason, 2016). However, one study shows that Asian Indians and Filipinos had higher prevalences of being overweight (35-37 percent and 35-47 percent respectively; Oza-Frank et al, 2009). This analysis, along with many others, shows that Asians—no matter the ethny—have higher levels of body fat than non-Hispanic white populations. It’s also worth noting that Filipina women had higher levels of VAT (visceral adipose tissue) than whites of a similar BMI and WC (waist circumference; Araneta and Barrett-Connor, 2012).
Asian ethnies have differing levels of body fat at the same BMI. This implies that what works for whites regarding BMI won’t work for Asians, since these ethnies, when compares with whites of a similar BMI and WC, had higher rates of body fat. The relationship between BMI and body fat levels is ethny-specific (Deurenberg, Deurenberg-Yap, and Guricci, 2002), though Filipinos and Asian Indians have higher levels of body fat regardless of the BMI standard used (Oza-Frank et al, 2009), which is one of the most important tells in ascertaining whether one is at-risk for DM and other maladies. It is not particularly interesting that Asian emigrants to America see their weight increase, as this is noted when the scourge called the Western diet crosses the Pacific. But what is interesting here is the rates between each Asian ethny, what they eat, and what causes the relationship.
Asian ethnies, when matched at similar BMIs, had differing levels of body fat, which implies that there should be ethny-specific BMI, though no matter which BMI standard was used, Filipinos and Asian Indians still had higher rates of body fat.