Why it is harder to lose weight today than it used to be

An interesting article in todays paper on weight control and obesity caught my eye. The article suggests that excess weight is not only about calorie intake and lack of exercise. Recent research at the universities of York and Alberta, but based on US source data, suggests that it really is harder to lose weight today than it was 30 years ago, and that a person in 2008 who consumed exactly same amount of calories as a person in 1971 would actually be about 10% heavier on average.
Now, this is not a huge discrepancy, and the study emphasizes that by far the most important factors in weight regulation remain calorific intake and exercise. But for the first time (at least to my knowledge) the extent of the influence of hidden, environmental factors has been quantified. Among these environmental factors are:

• Constant exposure to low-levels of environmental chemicals (such as pesticides, growth, hormones, plasticizers, flame retardants, heavy metals, etc) may interfere with hormone levels and lead to increased fat stores.
• Exposure to these kinds of chemicals in the womb may have the effect of pre-programming the body for weight gain later in life.
• There has been a large increase in the prescription of drugs (e.g. for mood disorders, migraines, hypertension, diabetes, etc) for which weight gain is a major side effect.
• Chronic stress and lack of sleep in our increasingly 24/7 lifestyle may cause higher levels of the stress hormone cortisol, which is associated with abdominal fat gain and impaired blood-sugar control.
• Many different studies have shown that our modern gut flora is inferior in numbers, quality and variety - largely due to highly-processed, low-fibre diets that are high in fats and refined carbohydrates - one consequence of which is the reduced ability to absorb calories efficiently.

So, overeating and inactivity are still the main culprits, but we should probably also be avoiding plastic containers, getting more sleep, and eating more unprocessed and organic foods, and particularly foods like whole-grains, fruit, vegetables and yoghurt that encourage the growth of healthy gut bacteria, and even looking more closely at our medications.
Nothing we didn't already know really, but studies of this kind have a way of concentrating the mind a little more.