Subtitles section Play video Print subtitles Conventional wisdom about diets, including government health recommendations, seems to change all the time. And yet, ads routinely come about claiming to have the answer about what we should eat. So how do we distinguish what's actually healthy from what advertisers just want us to believe is good for us? Marketing takes advantage of the desire to drop weight fast, and be stronger, slimmer, and brighter. And in the big picture, diet plans promising dramatic results, known as fad diets, are just what they seem: too good to be true. So where do diet fads even come from? While the Ancient Greeks and Romans rallied behind large-scale health regimens centuries earlier, this phenomenon began in earnest in the Victorian Era with crazes like the vinegar diet and the Banting Diet. Since then, diets have advised us all sorts of things: to excessively chew, to not chew at all, to swallow a grapefruit per meal, non-stop cabbage soup, even consumption of arsenic, or tapeworms. If the idea of diet crazes has withstood history, could this mean that they work? In the short term, the answer is often yes. Low-carbohydrate plans, like the popular Atkins or South Beach Diets, have an initial diuretic effect. Sodium is lost until the body can balance itself out, and temporary fluid weight loss may occur. With other high-protein diets, you might lose weight at first since by restricting your food choices, you are dropping your overall calorie intake. But your body then lowers its metabolic rate to adjust to the shift, lessening the diet's effect over time and resulting in a quick reversal if the diet is abandoned. So while these diets may be alluring early on, they don't guarantee long-term benefits for your health and weight. A few simple guidelines, though, can help differentiate between a diet that is beneficial in maintaining long-term health, and one that only offers temporary weight changes. Here's the first tipoff: If a diet focuses on intensely cutting back calories or on cutting out entire food groups, like fat, sugar, or carbohydrates, chances are it's a fad diet. And another red flag is ritual, when the diet in question instructs you to only eat specific foods, prescribed combinations, or to opt for particular food substitutes, like drinks, bars, or powders. The truth is shedding pounds in the long run simply doesn't have a quick-fix solution. Not all diet crazes tout weight loss. What about claims of superfoods, cleanses, and other body-boosting solutions? Marketing emphasizes the allure of products associated with ancient and remote cultures to create a sense of mysticism for consumers. While so-called superfoods, like blueberries or açaí, do add a powerful punch of nutrients, their super transformative qualities are largely exaggeration. They are healthy additions to a balanced diet, yet often, they're marketed as part of sugary drinks or cereals, in which case the negative properties outweigh the benefits. Cleanses, too, may be great in moderation since they can assist with jumpstarting weight loss and can increase the number of fresh fruits and vegetables consumed daily. Scientifically speaking, though, they've not yet been shown to have either a long-term benefit or to detox the body any better than the natural mechanisms already in place. Everywhere we look, we're offered solutions to how we can look better, feel fitter, and generally get ahead. Food is no exception, but advice on what we should eat is best left to the doctors and nutritionists who are aware of our individual circumstances. Diets and food fads aren't inherently wrong. Circumstantially, they might even be right, just not for everyone all of the time.