We have all heard the message that excess body fat is the result of eating too many calories and not getting enough exercise. If only it were that simple. Weight gain can also be due to factors in our diet and the environment that we are not even aware of.
1. Environmental Chemicals
Many environmental chemicals have resulted in weight gain when tested on animals in low, non-toxic doses. Examples include heavy metals, solvents, refrigerants, pesticides, and plastics (such as BPA, which is used in food and beverage containers).
Some of these chemicals known as endocrine disruptors can interfere with the hormones that control weight. There is even evidence to suggest that exposure to environmental chemicals in the womb may be associated with obesity later in life.
Emulsifiers are chemical substances that cause the oil to mix with water. They are used in a wide range of processed foods, including ice cream, mayonnaise, margarine, chocolate, bakery products and sausages.
A study in mice published in Nature found that emulsifiers alter intestinal bacteria, causing inflammation. Mice fed water containing emulsifiers became obese and developed the metabolic syndrome, a group of risk factors that increase the risk of heart disease.
Although the flavor enhancer MSG (monosodium glutamate) is associated with Chinese restaurants, it is used by major fast food chains and is also found in a variety of processed foods.
A study of 750 Chinese men and women found that those who used the most MSG in their kitchen were almost three times more likely to be overweight than those who did not use them. The increase in obesity risk was independent of physical activity and total calories consumed.
4. Artificial Sweeteners
Many people use sugar substitutes as an aid in losing weight, but these sweeteners can actually contribute to weight gain.
In a study published in Nature, the scientists found that mice fed saccharin, sucralose or aspartame developed glucose intolerance, a metabolic condition associated with obesity and type 2 diabetes. Artificial sweeteners altered the intestinal microbiomes of the animals towards a balance of bacteria associated with metabolic diseases.
In a follow-up study in 7 human volunteers, 4 became glucose intolerant after consuming the maximum recommended dose of saccharin for a week.
5. Low-Fat Foods
Gram per gram, fat has more than twice as many calories as protein or carbohydrate, so people tend to assume that foods labeled “low in fat” are good for losing weight.
In a study published in the journal Appetite, researchers analyzed the nutritional information of nearly 6,000 foods and discovered that, in general, products with low-fat properties were not significantly lower in calories than their total fat equivalents.
Low-fat foods can even lead people to consume extra calories. A study investigating the effects of different fats on satiety found that participants were less hungry two hours after eating regular muffins compared to non-fat muffins.
If you want to lose weight, you can help avoid processed foods, fast food and intensive culture food. Production methods, containers and ingredients may increase your risk of obesity.