Table 1.
Representative human studies on the effect of nontraditional risk factors of obesity
| Study population | No. of participants | Exposure | Main finding | Reference |
|---|---|---|---|---|
| ALAN | ||||
| Non-obese American adults (age, 50–71 yr) | 239,781 | Outdoor light at night (by satellite imagery) | 12% (Men) and 19% (women) higher odds of obesity in the highest quintile group | 29 |
| Women in US and Puerto Rico (age, 35–74 yr) | 43,722 | ALAN while sleeping | 19% Increase in the risk of incident obesity by ALAN exposure while sleeping 17% Increase in the risk of gaining ≥ 5 kg and 13% increase in the risk of BMI increase ≥ 10% by sleeping with a television or a light on |
30 |
| PM | ||||
| Chinese adults (age, 18 yr or older) | 13,741 | PM2.5 | 1 µg/m3 Increase of PM2.5 in the past 12 months increases overweight and obesity rate by 0.82 and 0.27 percentage points, respectively | 46 |
| Overweight and obese Latino children (age, 8–15) | 314 | PM2.5 | 4 µg/m3 Difference in long-term PM2.5 was associated with a 3 kg/m2 higher BMI and a 2% higher body fat percentage at age 18 | 48 |
| Chinese adults (age, 18–74 yr) | 24,845 | PM10 | 19 µg/m3 Increase of PM10 was associated with increased prevalence of overweight (8%) and obesity (12%) | 49 |
| Endocrine disrupting chemicals | ||||
| U.S. adults (age, 18–74 yr) | 2,747 | Bisphenol A | Higher odds of obesity (76%) and abdominal obesity (58%) in the highest quartile group | 67 |
| Women in US (age, 18 yr or older) | 6,005 | Phthalates | Positive association between BMI and MBP (OR, 1.13) or MEHP (OR, 1.12) Positive association between WC and MBP (OR, 1.13) Positive association between MEHP/MEHHP and BMI (OR, 1.21) or WC (OR, 1.20) |
75 |
| Reduced green space | ||||
| Employees in Finland | 25,317 | Distance to green space | Higher odds of overweight (OR, 1.50) in persons living > 750 m vs. < 250 m from a usable green area Higher odds of obesity (OR, 1.49) when moving away from the proximity of a green area (from < 250 m to > 250 m) |
83 |
| Danish adults (age, 16 yr or older) | 21,832 | Distance to green space | Higher odds of obesity (OR, 1.36) in persons living more than 1 km from green space than those living closer than 300 m | 85 |
ALAN, artificial light at night; BMI, body mass index; PM, particulate matter; PM2.5, particulate matter with a diameter of less than 2.5 μm; PM10, particulate matter with a diameter of 10 μm or less; MBP, monobutyl phthalate; OR, odds ratio; MEHP, mono-2-ethylhexyl phthalate; WC, waist circumference; MEHHP, mono(2-ethyl-5-hydroxyhexyl) phthalate.