Canadians pay billions of dollars a year to the diet industry, with some estimates putting its revenue at $7 billion. And while names like Weight Watchers and Atkins have become immediately recognizable (and celebrated or vilified, depending on the results they’ve yielded), new diets pop up all the time with promises of offering life-long changes.
But how many of them are actually effective and sustainable?
“The problem today is that people are so concerned with losing weight quickly, they don’t care about sustaining it six months down the line,” says Abby Langer, registered dietitian and owner of Abby Langer Nutrition in Toronto. “They want to be able to do something today and wear a bikini tomorrow, but you want to make changes that will last for the rest of your life.”
There seems to be a careful formula needed to create hype behind diets today — and that includes a doctor’s seal of approval, celebrity endorsement and health claims backed by self-serving science.
At the end of the day, Langer says, finding a diet that will work is as personal as finding the right swimsuit. What might work for one may not work for another.
We’ve examined the six most popular diets today and asked the experts to weigh in on their claims and effectiveness.
#1 The Whole30
What it is: A diet that claims to “re-set” your body, and rid you of any food, skin or seasonal allergies by eliminating foods that cause inflammation and cravings. It’s a hardcore program that needs to be followed for 30 days with no interruptions. “Just a small amount of any of these inflammatory foods could break the healing cycle,” the website states. “One bite of pizza, one spoonful of ice cream, one lick of the spoon mixing the batter within the 30-day period and you’ve broken the ‘reset’ button, requiring you to start over again on Day 1.” Bonus: the diet strongly advises people against weighing themselves to measure progress.
What you eat: Moderate portions of meat, seafood, eggs, vegetables, some fruit, natural fats, herbs, spices and seasoning. (Coffee and tea allowed.)
What you eliminate: Real and added sugar, alcohol, grains, legumes, dairy and soy.
What the experts say: Langer calls this “basically a cleanse,” but says the rationale behind cutting out healthy foods like dairy and whole grains, is based on poorly done research, and its restrictions make it virtually impossible to follow if you follow a plant-based diet. In addition, it sends a problematic message.
“What’s very disturbing about it is the insulting and punitive way it treats people. The people who wrote the diet claim it ends your relationship with unhealthy food, but I think it will start a new unhealthy relationship with food. It’s unforgiving, and if you don’t follow it, you’ve failed,” she says.
#2 The Dukan Diet
What it is: Created by Dr. Pierre Dukan, a French neurologist and general practitioner, the diet consists of four phases that are meant to change your eating habits forever through a high protein, and low-fat and carbohydrate program. It boasts a list of 100 foods that are allowed on the diet and claims “no frustration and no starvation.” In phase one (“Attack” phase), you eat pure protein foods; phase two (“Cruise”) introduces non-starchy vegetables; phase three (“Consolidation”) gradually re-introduces starches; and phase four (“Stabilization”) allows all foods but requires consumption of three tablespoons of oat bran per day and one pure protein day per week.
What you eat: Lean meat, poultry, fish, shellfish, vegetarian proteins (soy, tempeh, tofu), fat-free dairy, eggs and vegetables. (Coffee, tea, unsweetened drinks and no more than one can of diet soda is allowed. No alcohol.)
What you eliminate: At the beginning, you only eat pure protein and other foods are re-introduced slowly throughout the phases. Oat bran is required every day through the entire program to boost fibre intake.
What the experts say: Thrust into the spotlight after it was revealed that Kate and Pippa Middleton followed this diet leading up to the Duchess’s wedding (“it got popular thanks to Pippa’s butt,” Langer quips), the experts once again take issue with Dukan’s restrictiveness.
“To be balanced and healthy it needs to have more focus on plant-based foods,” says Andrea Hardy, a registered dietitian in Calgary and owner of Ignite Nutrition. “Eating all that meat means you’re missing an opportunity to get phytochemicals, antioxidants and nutrients from fruits and vegetables.”
She also points out that the absence of fibre means you’ll lack healthy gut bacteria, which can lead to long-term health problems like anemia, high cholesterol and osteoporosis.
#3 The Paleo Diet
What it is: Created to mimic the way our ancestors ate (like in the Paleolithic period), this diet claims to lead to weight loss, optimize health and minimize the risk of chronic disease. This is another high protein, low carb diet that emphasizes non-starchy fruits and vegetables that won’t spike your blood sugar, and promotes moderate to high consumption of monounsaturated and polyunsaturated fats. It especially vilifies whole grains and dispels the notion that they are a rich source of fibre. In other words, if the hunter-gatherers before us didn’t eat it, neither should you — with the exception of the three non-Paleo meals per week that you’re allotted. (That’s when you can have wine.)
What you eat: Meat, poultry, fish, (non-starchy) fresh fruits and vegetables, eggs, nuts and seeds, and healthy oils. (Moderate amounts of green tea allowed.)
What you eliminate: Grains, legumes, dairy, refined sugar, potatoes, processed food, salt and refined vegetable oils, coffee.
WATCH BELOW: Global News explores diets and dieting
What the experts say: Ultimately, Paleo is a sustainable diet for some people and is especially attractive to meat lovers. But, Hardy warns, a lot of people do Paleo wrong and fail to round out their protein-heavy meals with fruit and vegetables. In addition, its highly restrictive nature could end up driving people to consume unhealthy grains for a “cheat meal” which in turn muddies the relationship with healthy carbs.
“If it’s too restrictive, people will end up feeling like they’ve ‘fallen off the wagon’ when they consume grains, and will, therefore, gravitate to something unhealthy like a doughnut because they’re ‘cheating,’ instead of choosing a wholesome grain product,” she says.
#4 The Mediterranean Diet
What it is: This predominantly plant-based diet draws from the traditional foods consumed by Mediterranean dwellers (like Italians, French and Greeks). It has been shown to reduce the risk of heart disease and lower cholesterol, and is associated with reduced incidences of cancer, Parkinson’s and Alzheimer’s disease. It promotes healthy fats as well as lots of fresh fruits, vegetables and whole grains, some fish and very little red meat.
What you eat: Vegetables, fruits, nuts, seeds, legumes, potatoes, whole grains, breads, herbs, spices, fish, seafood and extra virgin olive oil. Poultry, eggs, cheese and yogurt should be eaten in moderation, and red meat should be eaten rarely. (Wine, coffee and tea are allowed.)
What you eliminate: Added sugar, refined grains, trans fats, processed meats, refined oils, highly processed foods.
What the experts say: This diet scored top marks for being sustainable, healthy, and well-researched to prove it lowers cholesterol and has anti-inflammatory effects.
“The idea is that you’re eating less animal protein, and less protein in general,” says Jessica Begg, registered dietitian and owner of Shift Nutrition in Calgary. “The protein powder industry has put so much emphasis on protein and we’re eating too much of it.”
She lauds the Mediterranean diet for focusing on sources of healthy fats and for not being restrictive.
“You’re not going to find a hack on Pinterest for a ‘Mediterranean chocolate cake,’ because it pushes a healthy balance of whole foods and allows almost everything,” Hardy says.
She says it’s not necessary to completely adopt it, either. People can slowly incorporate elements of the Mediterranean diet into their lives, like swapping out peanut oil for olive oil and eating pulses once a week, and they’ll still reap some benefits.
#5 The Alkaline Diet
What it is: The premise of this diet is that it will neutralize and balance the body’s natural pH by eliminating acidity. Our kidneys are responsible for maintaining our electrolyte levels, but chronic exposure to an acidic environment will cause those levels to deplete and result in acidosis. This acidity “robs” essential minerals from our bones, cells, organs and tissues, and accelerates the aging process, leads to a gradual loss of organ functions, and degenerates tissue and bone mass. By eating alkaline foods (like fresh fruits and vegetables, and unprocessed plant-based protein) you’ll stave off chronic health issues like diabetes, hypertension, arthritis and low bone density. It also pushes organic foods because research says the type of soil plants and vegetables grow in can influence their vitamin and mineral content.
What you eat: Fresh fruits and vegetables (preferably organic and raw), plant proteins (including soy and tofu), limited quantities of meat (preferably organic), alkaline water, green drinks made from green vegetables and grasses, and some dairy (like probiotic yogurt and kefir).
What you eliminate: Processed foods, processed cereals, eggs, lentils, fish, oats and whole wheat products, milk, peanuts and walnuts, pasta, rice, bread, alcohol, caffeine.
What the experts say: This one is plain bunk, experts say.
“There’s absolutely no evidence to support that this is a thing,” Begg says. “The premise is that you’re trying to maintain an alkaline system but our pH levels are tightly controlled by our bodies.”
Langer echoes her sentiments and calls this diet “a mockery of basic physiology.”
“This diet claims that cancer grows in an acidic environment, but in actuality, cancer creates the acidic environment,” she says, therefore the research has it backwards.
Hardy agrees that there’s no scientific evidence to back up the diet’s claims of alkalinity — “your kidneys and lungs act as a buffer for you and help maintain your pH regardless of what you eat” — but appreciates its focus on fresh fruits and vegetables.
#6 Intermittent Fasting
What it is: The concept of this diet is to “feast” and then fast for an extended period of time. Its roots date back to the 1930s, when researchers were trying to determine the benefits of reducing calorie intake by skipping meals. During that time, a scientist noticed that significantly reducing calorie intake helped mice live longer. Since then, more studies were conducted (on monkeys, fruit flies and roundworms) and in all cases, a reduced calorie diet was linked to longevity and lowered risk of common diseases. It is credited with burning fat, since during the extended fasted phases, your body doesn’t have food to burn for energy so it will naturally burn your stores of fat. As a result, it will promote weight loss and build muscle.
What you eat: It’s not what you eat, but how you eat. The 16/8 method involves fasting for 16 hours and eating all your calories within an eight-hour window. The 5:2 plan involves eating normally for five days and consuming no more than 600 calories for two days. Eat-Stop-Eat involves fasting for 24 hours once or twice a week; alternate day fasting requires you to fast every other day, although some plans allow 500 calories on fasting days; the “Warrior” diet involves eating a small amount of raw fruits and vegetables during the day and a large meal at night; and spontaneous meal skipping allows you to decide which meals to skip and when. In all cases, it is recommended to eat a healthy, balanced diet of whole foods, and to avoid processed and junk foods as they aren’t filling.
What you eliminate: Food.
What the experts say: This diet sounds rigorous and outlandish, but it has “good scientific evidence” to back it up, Hardy says. The main issue is eating the right things during the “feasting” phase.
“I’ve had clients do this and end up gaining weight because they eat whatever they want within that time frame without honouring their hunger and fullness,” she says.
The other concern is that it could trigger an already tenuous relationship with the way a person eats.
“Emotionally it can be very triggering for a person who struggles with an eating disorder because it promotes starving and bingeing,” Langer says.
She says it could be beneficial for anyone who has “lost their hunger cues” due to over-dieting (this can happen to people who diet all the time and are accustomed to always being hungry) because it’ll become very clear what real hunger feels like.
“But if you aren’t able to control yourself when it’s time to eat because you’re so hungry, that’s a problem.”