Facts about weight & obesity

Eating disorders are complex systems. They are more than weight and body size, and yet they typically involve an obsession with weight and body size. The following facts are intended to help parents relax about their children’s weight and to help their children do the same.

Key points

If you exercise, eat nutritiously, avoid weight cycling, and get good quality medical care, you don’t need to worry about obesity shortening your life. [1]

If a ‘cure’ for obesity is defined as a reduction to ideal weight and maintenance of that weight for 5 years, a person is more likely to recover from most forms of cancer than from obesity. [2]

The idea that every body can attain a certain level of thinness is preposterous. Can we all be the same height? Can we all be the same race? Can we all have the same eye color? [16]

People who are overweight or moderately obese live at least as long as normal weight people, and often longer. [17, 18, 19, 20]

1. The genetics of weight

Genetics drive the majority (70%) of your body weight, as shown in numerous twin studies. Bodies tend to stay within about 15 lbs above and 15 lbs below a “set weight,” regardless of diet, exercise, and willpower. If you push your body out of this range, it will push back with biological systems. [2]

Adopted children’s weight is correlated strongly with the weight of their biological parents, and almost not at all with the weight of their adoptive parents. [3]

Genes drive 70% of your body weight, and they drive 80% of your height. We never talk about influencing our height, but we always talk about influencing our weight, even though they are mostly pre-programmed from conception. [1]

2. The science of obesity

The science of obesity is largely driven by grants, monetary donations and other payments from the diet industry. For example, authors of the papers frequently used to drive headlines about the dangers of obesity cite conflict of interest statements including funding received from diet companies like Weight Watchers, Jenny Craig, and Slim-Fast, and pharmaceutical companies building weight loss drugs like Xenical, Meridia, and Redux. [9]

Eight out of nine members of the National Task Force on the Prevention and Treatment of Obesity, funded by the federal government to set national health policy, each had financial ties to between two to eight pharmaceutical companies and commercial weight loss companies. [16]

3. The science of getting fat

It’s just as hard to make people become obese as it is to get obese people to become thin. Even massive overfeeding has been shown ineffective at achieving and maintaining obesity. [4]

Researchers can feed an exact number of calories to people and control their activity, and there is still not a direct correlation between calories in/out and weight gain/loss. [1]

4. Correlation vs. causation

There are zero studies that show that obesity causes health problems. [1]

Due to the fact that it’s very hard to prove causation, one of the only factors we can really measure is the rate of death from obesity. In other words, if being obese is “deadly,” then people who are obese should have shorter life spans than thinner people. But this is not true. [1]

The ratio of risk for lung cancer among smokers compared to nonsmokers is 30, while the risk ratio for earlier death for people who are overweight through obesity class II is 1. This means it is very, very low. [1, 6]

There is a higher correlation between someone’s initials (e.g. B.A.D. vs. W.I.N) and their health than there is between someone’s weight and their health. Someone with negative-correlation initials lived an average of 7 years less than someone with positive-correlation initials. Meanwhile, your life expectancy may be 6 years shorter than someone of average weight if you are class I obese. [5]

5. Obesity and death

Based on age at death, overweight people are at least as healthy as normal-weight people, and even have a slightly higher age of death than normal-weight people. [1]

When socioeconomic and other risk factors are controlled for, obesity is not a significant risk factor for mortality; and… for those 55 or older, both overweight and obesity confer a significantly decreased risk of mortality.” [21]

Data in the elderly (among whom more than 70 percent of all deaths occur) found no evidence of excess mortality associated with overweight [22].

6. The obesity paradox

It has been shown that overweight and obese people are more likely than normal-weight people to be diagnosed with diseases like diabetes and cardiovascular disease. [7]

However, while obesity has increased from about 15% of Americans in the 1970s to almost 36% in 2010, the prevalence of diabetes increased from 9% to just 11%, and rates of cardiovascular disease have actually decreased from 12% to 11%. [8]

Strangely, once someone is diagnosed, overweight and obese people have a better prognosis than normal-weight people. This has been proven for cardiovascular disease, stroke, diabetes, kidney disease, chronic obstructive lung disease, rheumatoid arthritis, Pneumonia, and advanced lung and prostate cancer. [1]

This phenomenon is called the obesity paradox and is well documented in scientific literature.

7. Weight bias, fatphobia and the stress of being fat

While most people will not openly speak negatively about someone due to the color of their skin or gender, people openly criticize people who are overweight and obese. [10]

Weight discrimination is real, pervasive, and has serious health consequences. [11]

Weight stigma has been shown to lead to a physiological stress response. [15]

Religion, gender, and ethnicity are protected by law, but weight discrimination is not federally protected, and Michigan is the only state that prohibits it. [12]

More than 70% of obese women reported that in a single week they experienced negative comments and dirty looks. [13]

It is common for people who are obese to be approached by complete strangers offering weight loss and fashion recommendations. [14]

Facts about diets & weight loss (1)

Learn the true facts about diets and weight loss, and why you and the people you love should never, ever diet.


[1] Mann, Secrets from the Eating Lab

[2] K.D. Brownell, “Obesity: understanding and treating a serious, prevalent and refractory disorder

[3] Eleanor Wheeler et al., Genome-wide SNP and CNV analysis identifies common and low-frequency variants associated with severe early-onset obesity

[4] E.A. Sims, “Experimental obesity, dietary-induced thermogenesis and their clinical implications

[5] Christenfeld, Phillips, and Glynn, “What’s in a name: morality and the power of symbols”

[6] Freedman et al. “Cigarette smoking and subsequent risk of lung cancer in men and women”

[7] Guh et al., “The incidence of co-morbidities related to obesity and overweight: a systematic review and meta-analysis”

[8] National Center for Health Statistics, 2013

[9] Olshansky et al., “A potential decline in life expectancy int he United States in the 21st Century”

[10] Nosek et al., “Pervasiveness and correlates of implicit attitudes and stereotypes

[11] Puhl, Andreyeva, Brownell, “Perceptions of weight discrimination: prevalence and comparison to race and gender discrimination in America

[12] Suh et al., “Support for laws to prohibit weight discrimination in the United States

[13] Seacat, Dougal, and Roy, “A daily diary assessment of female weight stigmatization”

[14] Poulton, No Fat Chicks

[15] Schvey, Puhl, and Brownell, “The stress of stigma”

[16] Matz, Frankel, The Diet Survivor’s Handbook’

[17] Flegal KM, Graubard BI, Williamson DF, Gail MH, “Excess deaths associated with underweight, overweight, and obesity”

[18] Durazo-Arvizu R, McGee D, Cooper R, Liao Y, Luke A, “Mortality and optimal body mass index in a sample of the US population”

[19] Troiano R, Frongillo E, Sobal J, Levitsky D, “The relationship between body weight and mortality: A quantitative analysis of combined information from existing studies”

[20] Flegal K, Graubard B, Williamson D, Gail M: Supplement, Response to “Can Fat Be Fit”

[21] Lantz PM, Golberstein E, House JS, Morenoff J, “Socioeconomic and behavioral risk factors for mortality in a national 19-year prospective study of U.S. adults”

[22] Janssen I, Mark AE, “Elevated body mass index and mortality risk in the elderly”