While somewhat less sinister, added sugar can also wreak major damage on a diet.
Technically low in calories, high-quantities of sugar disrupts our metabolisms, causing surges in insulin and energy levels and ultimately contributing to weight gain and diabetes.
Consumption of added fats also shot up by around two thirds over the same period, and grain consumption rose 45% since 1970.
Research published by the World Health Organization found that a rise in fast food sales correlated to a rise in body mass index, and Americans are notorious for their fast-food consumption ― such food makes up about 11% of the average American diet.
Experts said the survey’s results indicate that many factors are contributing to Americans’ obesity, and they don’t all have to do with food. They concluded that overall diet, including calories from grains, oils and dairy fats, combined with physical exercise and portion control, mattered much more than targeting specific foods.
In fact, there have been some positive signs that Americans are changing the way they eat. The researchers concluded that these changes in energy intake were independent from economic conditions or food prices, and public health efforts were likely to have helped. (And, to be clear, that doesn’t mean gorging on junk food won’t make you overweight.) Still, despite recent findings, there is still work to be done about the foods Americans eat.Lack of exercise is also a major culprit in the obesity epidemic.It's been decades since most Americans worked in fields and on factory floors, a far greater majority of us are sitting throughout our workday. According to one study, only 20% of today's jobs require at least moderate physical activity, as opposed to 50% of jobs in 1960.It's no wonder we're looking for fast food and fast weight loss options, we spend more time at work and less time in our homes and kitchens than our parents did.Sometimes you only have time to pack a leftover pizza slice and a slim-fast for lunch, irony be damned.A number of other factors are thought to play a role in the obesity epidemic, such as the in utero effects of smoking and excessive weight gain in pregnant mothers.Poor sleep, stress, and lower rates of breastfeeding are also thought to contribute to a child's long term obesity risk.Other research suggests Americans burn 120 to 140 fewer calories a day than they did 50 years ago.Add this to the higher amount of calories we are packing in, and we get a perfect recipe for weight gain. It is also how we get to work and what we do after.Americans walk less than people in any other industrialized country, preferring to sit in cars to get around.And at the end of the day, 80% of Americans don't get enough exercise, according to the CDC.