Pollution would also increase substantially. Garbage would increase by 80 million tons a year, and climate-warming carbon dioxide gases would increase by 3 billion tons. The increase in human size would also have a substantial impact on rainforests, freshwater resources and biodiversity. In addition to having an adverse effect on the environment, a larger body size holds almost no advantage for the individual - except in our minds. In fact, the lifestyle that has promoted the growth of larger human bodies over the last 100 to 150 years, which includes a high-calorie diet, has also created an epidemic of heart disease, diabetes, and cancer.
Japan provides an example.
After WWII, the US shipped meat, dairy products and eggs to Japan and thereby modified traditional Japanese eating habits. As a result, Japan's population grew taller and heavier, and now have an increased propensity for heart disease, breast cancer, and other diseases that may stem from a rich diet. An extensive Chinese study found that taller, heavier subjects had higher death rates from cancer and heart disease. A 1990 World Health Organization report supports these nutritional findings and cautions developing countries against copying Western dietary practices. The Journal of the Washington Academy of Sciences study presented extensive data showing that smaller people live somewhat longer than taller people.