For those of you who are down on yourselves because you can’t lose weight, please realize the complexity of the issue. Forget will power and self-discipline, calories in and energy out. The truth is, many factors affect our eating and size.

Out of body experiences by Julie Deardorff (Sarasota Herald Tribune, Health and Fitness, 10/30/12) provides the lowdown on how our weight is affected by environment. I guarantee that on your own you’d never have imagined that some of these factors would impact your weight, so three cheers for scientific studies.

• Pregnant women who breathe high levels of diesel fuels/hydrocarbons are more
  likely to have obese children than those who don’t. These chemicals can be found outdoors, but are also in “cigarette smoke, candles, incense, and home heating fuels.”
• The intake of antibiotics in infancy may upset the balance of gut bacteria which
  in turn affect “hormones related to metabolism.”
• Sleep deprivation “may decrease resting metabolic rates, or the number of calories
  burning while doing nothing” and alter “the circulation levels of the hormones that control hunger.”
• “Children of older women are more likely to be obese” and “overweight pregnant
  women can…pre-program their offspring for obesity.”
• “Inhaling increased amounts of carbon dioxide,” making blood more acidic, may lead
  to “increased appetite and decreased activity.”
• Because colder temperatures can activate calorie-burning brown fat, higher room
  temperatures inadvertently may be helping us store more calories.
• Air-conditioning keeps folks indoors rather than outdoors where they get more
  exercise. Moreover, when we allow our bodies to get hot, we end up eating less.
• Bisphenol A (in plastics) and other chemicals may “mimic or block the body’s
  hormonal actions” which may cause obesity in children.
• Respiratory or gastrointestinal infections “may infect fat cells, making them grow
  more quickly.”
• Some medications may promote weight gain.
• Because “nicotine increases energy expenditure and may reduce appetite,” people
  may gain weight after stopping smoking.

As you know, I’m all for focusing on eating, not weight, but it’s important for you to realize that there are factors outside your control that affect your size. So, please, go a little easier on yourselves. You can only do what you can do.