With Christmas over and the New Year firmly upon us Aoife Hardesty looks at the science behind the many so called ‘miracle diets’ and questions how safe they are
Every January people are bombarded with “ways to help you lose weight!”. Gym memberships are on offer, Operation Transformation returns to the telly screens and the latest diets appear. Struggling to lose weight is something which plagues so many people. After the Christmas binge, many people want to lose weight. “Fad diets” can often seem like the best way of doing this.
Fad diets are diets which promise success in the short term. They often mean eliminating one or more food groups, or they can involve living on one substance only. Here we explore some fad diets and the science behind them.
The famous Atkins Diet relies on eliminating carbs from the diet, thus causing your body to rely on its fat storage for fuel. When the body is no longer getting carbohydrates or other sugars that it needs for energy it breaks down fat in a process called ketosis. The dieter is encouraged to eat products high in fat such as meat and fish and not breads, pastas, or dairy products other than butter, cheese and cream. The science behind this diet checks out, but long term effects may be mixed. Research has shown that there is a higher incidence of heart disease, blood pressure problems and high cholesterol levels for people on the diet who relied on animal fat and protein than for people on the diet who got their fat and protein from and plant sources.
The Hollywood Diet is all about grapefruit. It is a low carb diet where portions of grapefruit are eaten before meals which consist mainly of fats and proteins with little carbohydrates. What supposedly makes the grapefruit such a magical fruit is that it apparently contains a fat-burning enzyme. Studies have debunked the myth of grapefruit’s magical enzyme but the diet may still cause some weight loss. Loss of weight for individuals on this diet is probably due to the high water content within grapefruit which makes the eater feel fuller quicker and thus eat less. Upon a return to normal eating, the results usually disappear.
The dieter swallows a tapeworm after eating, allowing the tapeworm to gobble up all the food passing through the dieter’s digestive system.
The Paleo diet takes us back to the prehistoric times of the cavepeople. Back in the olden days, people didn’t farm, they didn’t have cereals to make breads and pastas, they didn’t keep animals for dairy, and of course, they had not yet developed processed foods, meaning no pickles. The rules are to eat non-starchy vegetables, fish, lean meat, fruits and nuts. Eating the food on this diet means you are returning to eating what the first humans ate, so the theory is that you are eating the healthy food that humans were originally supposed to eat. The main concern for this diet is the elimination of dairy, the dietary source of calcium, which results in weaker bones. The argument for the paleo diet is that humans were never supposed to start absorbing the excess calcium from dairy products, but studies on genes for metabolising dairy products show such genes emerged around the time when humans first started farming. These genes spread through the population until it became the new normal for people to be able to metabolise dairy products.
The VB6 diet stands for Vegan Before 6pm. So dieters eat a vegan diet up until 6pm, after which they can eat whatever they want. During the day the dieter may indeed be eating more low-fat foods, but after 6 pm, those unsatisfied with their meals up to then will take the opportunity to eat piles of snacks and junk food, negating the effect of all that healthy food. The theoretical science behind this diet is that after 6pm any foods that are high in fats or sugars that would normally be considered “unhealthy” do not have the same effect as they would have if they were consumed during the day, however this is untrue. The food you eat will have the same effect no matter what time of day you eat it at.
The Tapeworm diet involves swallowing tapeworms. Yes you read that correctly. The dieter swallows a tapeworm after eating, allowing the tapeworm to gobble up all the food passing through the dieter’s digestive system. However, having a tapeworm in one’s digestive system causes an immune response resulting in the tapeworm leaving the digestive system and entering the bloodstream. From the bloodstream, the tapeworm can travel to the brain from which it cannot be removed and where it causes irreparable damage, eventually resulting in death. Not worth it.
Dieting well should mean the dieter is burning off more calories than they are putting into their bodies. Essentially what the dieter should be doing is exercising more, decreasing portion sizes at meal times, putting an end to snacking between meals and decreasing intakes of foods that are high in sugars and high in fats (those foods we tend to refer to as “junk foods”).
One of the main problems with fad diets is that they’re often shortlived; the individual diets for a couple of weeks or, for longer-lived diets, a couple of months, and the dieter loses an awful lot of weight within that period of time. But once the individual is no longer dieting, they put on a significant amount more weight. Why is this? Because you’ve been convincing your body that it’s being starved and your body’s way of dealing with that is to build up a greater fat store for the next time you might end up starving. The best way of losing weight to ensure you stay at your desired weight for years (ensuring you keep up your proper eating and exercise regime) is to lose weight slowly and steadily. The results do not appear as quick but they are longer lasting, and there is no need for tapeworm.