Fad Diets: Why they "work" but really don't
Everyone has at least heard of someone who has dropped lots of weight fast on a fad diet, and felt at least a little bit of temptation to try it themselves. If these diets didn't work, why else would the weight loss industry be worth billions? The problem is, almost all people who lose weight on a commercial program gain it all back, and sometimes more, within two to three years. How come these diets don't seem to produce long-lasting results? We examine three popular ones to find out:
Atkins Diet
The father of all low-carb diets, the Atkins Diet is based on the idea that by restricting carbohydrates, your body's insulin production will decrease. When the insulin levels of your body are low, it will prefer to metabolize stored fat into compounds called ketone bodies for energy instead of glucose. This state is called ketosis.
The Induction phase of the Atkins Diet only permits dieters to eat 20 g of “net carbohydrates” (total amount of carbohydrates minus fibre, which contributes minimally to any rises in blood sugar). Afterwards, 5 g of carbohydrates are added every week until the person is 5-10 pounds within their goal weight. Finally, in the Pre-Maintenance and Maintenance phases, more carbohydrates are gradually re-introduced into the diet until the goal weight is reached and maintained, respectively.
Why it “works”
Carbohydrates make up about 50-65% of the average diet. Thus, it is easy to see why when people cut out these staples from their diet, they lose weight. People who are on the Atkins Diet often experience rapid weight loss in the beginning as well, due to water loss as their glycogen stores (our bodies' way of storing glucose) are used up. However, long-term studies have shown that the Atkins Diet promotes similar fat and weight loss to programs that prescribe a similar caloric intake.
Why it doesn't work
Glucose is the preferred source of energy for our brain and muscles. While they can run on ketone bodies when our body is in ketosis, many people experience negative side effects when they first start reducing their carbohydrate intake, such as mood swings, sluggishness, leg cramps and headaches. Ketosis also slightly increases the acidity of our bodies, so some people experience bad breath and strong smelling urine. People with diabetes (especially Type 1) should not go on the Atkins Diet, or any other diets that promote ketosis, as they cannot produce insulin to regulate the ketosis, leading to a dangerous condition called ketoacidosis.
The Atkins Diet also does not leave much room for flexibility. Just as the low-carb diet can cause rapid water loss, adding carbs back into the diet can cause rapid weight gain, making it discouraging for dieters.
It may be possible to adopt a healthy eating pattern on the Atkins Diet if people plan their diets in a way that ensures that they eat a lot of high-fibre vegetables — excellent sources of vitamins, minerals and antioxidants — while keeping net carbs low. However, the Atkins Diet eliminates many healthy foods like fruit, legumes and whole grains, while promoting foods high in saturated fat and calories.
Master Cleanse
Arguably the most well-known and simplest “detox” diet, the Master Cleanse was made famous when Beyonce admitted that it was the plan that she followed to lose weight in preparation for her role in the movie Dreamgirls. Also known as the “Lemonade Diet”, people who are on the cleanse are only allowed to drink a mixture of lemon juice, grade B maple syrup, cayenne pepper and water throughout the day. Cleansers must also drink a “salt flush” (a litre of water with two teaspoons of salt) in the morning, and a laxative tea at night. The Master Cleanse lasts a minimum of 10 days, though Stanley Burroughs, the creator of the diet, claims that there is enough nutrition to allow people to function the cleanse for up to 40 days!
Why it “works”
It would be impossible to not lose weight while eating essentially nothing for 10 days, and taking laxatives to boot!
Why it doesn't work
Despite their popularity, there is no scientific literature on detox diets or cleanses - have you ever noticed that they never tell you what the toxins are, or how to tell when they're out of your body? As long as your liver and kidneys are healthy, your body does not need any extra “detoxing”.
The Master Cleanse is highly deficient in nutrients - it lacks protein, fat, fibre and provides inadequate amounts of most vitamins and minerals. To make matters worse, the laxatives cause dieters to lose extra fluid and electrolytes. Many people report that they feel dizzy or weak while on the cleanse; proponents of the diet report that that is a side effect of the body ridding itself of its toxins, when really, it is the body saying that it is starving!
Most importantly, the Master Cleanse does nothing to teach people how to eat healthfully. As soon as the cleanse is finished, many return to their normal eating habits and quickly regain any weight lost, which was most likely water weight anyway.
Dukan Diet
Dr. Pierre Dukan has been promoting his high-protein, low-fat, low-carb diet for over 30 years in France, but his book was only translated for the UK and the US just over the past year. It was reported that Catherine, the Duchess of Cambridge, went on the diet to slim down for the royal wedding, along with her mother, Carole.
The diet is broken down into four phases - the Attack phase, a short, initial phase where people are allowed to only eat protein foods; the Cruise phase, the main weight loss phase where dieters are allowed to eat unlimited amounts of a list of 100 foods (including 28 vegetables) while alternating “protein only” and “protein and vegetable” days; the Consolidation phase, where fruit, whole grain bread, higher fat meats and cheeses and “celebration days” are gradually introduced after a person reaches their goal weight; and the Stabilization phase, where people are allowed to eat whatever they like, as long as they follow the basic guidelines of the Consolidation phase. In all phases, including the Consolidation and Stabilization phases, dieters must maintain one "protein only" day per week. People following the Dukan Diet are also encouraged to drink plenty of fluids, walk and take up to 2 tbsp of oat bran daily.
Why it “works”
In some ways, the Dukan Diet is like an updated version of the Atkins Diet - both are low carb diets, and thus promote weight loss via water loss and ketosis (especially in the Attack phase). The high protein content of the diet also promotes satiety, so people do not overeat, despite being allowed to have unlimited amounts of permitted foods. The Dukan Diet also limits high fat (and thus higher calorie) protein choices.
Both diets also work in phases, gradually allowing dieters to increase their carbohydrate intake as they reach their goal weight. Still, many people may find the Dukan Diet easier to follow as there is no carbohydrate counting - as long as the food is on the list, they are allowed to eat it.
Why it doesn't work
When the stages are all laid out in one tidy paragraph, the diet seems reasonable - people are eventually allowed to return to their normal eating habits, save one “protein only” day per week. However, depending on a person's goal weight, they may be stuck in the Cruise phase for a long time, which only allows a list of 100 foods. This can be restrictive both from a nutrition and quality of life standpoint.
Despite the fact that Dr. Dukan has promoted his diet in France for over 30 years, no formal studies have been done on the diet. While there are plenty of positive testimonials as more people jump on this new diet bandwagon, it may be interesting to see how things turn out as more people enter the Stabilization phase…
Bottom Line
People do lose weight on fad diets - otherwise they wouldn't be popular! As long as you are eating fewer calories, you will lose weight. The difficulty lies in ensuring that the weight comes off healthily and maintaining the weight loss. Many diets ignore a person's nutrient needs just so that the dieter can see the numbers coming down faster on the scale. Often, this only means that the weight will come back faster once that person reaches their goal weight and comes off the diet.
The only way to keep weight off for life is to “diet” for life, and the only way to “diet” for life is to adopt healthy, lifelong changes that take into account all your nutrition and health needs.
