The American documentary film Super Size Me by director Morgan Spurlock aimed to expose the evils of fast food. The film tracked the dire consequences of eating three McDonald’s meals a day for 30 consecutive days. Fast food retailers countered with the argument that their food was meant to be part of an overall balanced diet, not a complete way of eating.

During Spurlock’s experiment, he ate every item on the McDonald’s menu at least once and consumed on average double the number of calories recommended for an adult male. If the McDonald’s employee asked if he would like to “super-size” the meal he was obliged to say yes, but could not request it himself.

During the 30 days, Spurlock gained more than 11kg, and the effects on his overall health were dramatic. His cholesterol count shot up and he experienced side effects including mood swings, sexual dysfunction, and fat accumulation in his liver.

While Super Size Me was intended as a damning statement about the effects of fast food, Spurlock’s eating regime was not universally accepted as a legitimate experiment. Others subsequently repeated the exercise of eating only at McDonald’s for an extended period and demonstrated it was possible to do so and actually lose weight. They argued that Spurlock had deliberately chosen high-calorie options, including large quantities of soft drinks and shakes that were very heavy on sugar.

The film did have an effect on the fast-food chain. McDonald’s abandoned the practice of offering to super-size meals and began to include “healthier” options on its menus. Nonetheless, unless you opt for a salad and hold the dressing, it’s hard to find a meal at any of the major fast-food chains that you could actually call healthy. Even Subway, which purports to be a healthier option with its slogan “Eat fresh” can sell you a Chicken Parmigiana 12-inch Sub with 3640 kilojoules of energy, plus 28.8g of fat, 99.6g worth of carbs, 14.6g of sugars and 1810mg of sodium — “and that’s before you add extra sauce or cheese” Lifehacker advised.