If you have resolved to lose weight this year, you might be tempted to turn to fad diets for help. A fad diet is a way of eating that is restrictive and hard to sustain but promises to be the best way to drop weight and improve health.
In this article, we compare 7 of the most popular fad diets and explain the only real way to achieve weight loss.
The Most Popular Fad Diets
The Paleo diet, or Palaeolithic diet, involves eating foods which were supposedly eaten by our hunter-gatherer ancestors. It claims that our bodies have not evolved enough to eat foods that were developed in the relatively short time since the invention of agriculture. This diet includes eating only whole unprocessed foods like meat, fruit, vegetables, nut and seeds while restricting grains, legumes, dairy products, vegetable oils and any processed foods.
The Ketogenic diet, also known as Keto, has been around for a long time and has been used successfully to treat children with epilepsy. It has gained popularity in the past few years as a weight-loss diet because it focuses on shifting the body from using glucose as fuel to using fats (known as ketones), a state known as ketosis. It is an extreme low-carb and high-fat diet that encourages followers to eat a large percent of their calories in the form of fats while restricting carbohydrate intake to less than 50 grams per day.
Invented by cardiologist Dr. Atkins, the Atkins diet is a low-carb, high-protein and moderate-fat diet. It is set out in four stages, with the initial stage being the most restrictive and then slowly increasing the number of foods and carbohydrates that one can eat.
The Whole30 is a 30-day plan that aims to help you lose weight and improve health issues in a month. For 30 days, followers are told to abstain from dairy, grains, legumes, added sugar and sweeteners of any kind, sugary beverages, alcohol, food additives, processed junk foods and baked goods. It is similar to the Paleo diet in that the foods allowed include fruit in moderation, vegetables, meat without additives, eggs, seafood, nuts and seeds (excluding peanuts), coconut oil, olive oil and black coffee.
The low-fat diet is generally the diet recommended by conventional medical practitioners and healthcare systems for weight-loss. It involves getting only 10-30% of daily calories from fat sources. This means avoiding fatty cuts of meat, fried foods, full-fat products, nut butters and oils.
The raw food diet is a very restrictive form of veganism that proponents claim is good for weight loss and general health. It involves eating only raw and unprocessed foods like fruit, vegetables, nuts, seeds, sprouted grains and sprouted legumes, and avoiding cooked and refined foods. This stems from the belief that cooked food contains fewer nutrients, enzymes and “living energy” than raw food.
Intermittent fasting is a popular weight-loss method, but it isn’t a traditional diet because it controls WHEN you eat and not WHAT you eat. One of the most popular variations of this method includes only eating during an 8-hour window over 24 hours and fasting for the other 16 hours. Another variation involves fasting or severely restricting calories on two non-consecutive days during the week and eating normally on the other 5 days.
Why These Diets Work... and Don’t Work
So, you may be wondering why so many people have success with many of the popular fad diets mentioned above.
The reason these diets work for some people is that they indirectly reduce the number of calories eaten. Some of them do this by eliminating entire food groups, as in the case of the Paleo diet, Whole30, the Atkins diet, the Ketogenic diet and the raw food diet. You will inevitably lose weight if you remove many of the hyper-palatable and high energy foods that you were previously eating regularly.
The low-fat diet reduces overall calorie consumption because fats contain 9 calories per gram and protein and carbs only 4 calories per gram. Intermittent fasting also works by indirectly reducing the amount of calories consumed during the day or the week.
Low-carb diets like Atkins, Paleo, Whole30 and Keto have been shown to decrease calorie consumption by increasing feelings of fullness and reducing cravings (1, 2). This is likely due to the increase in satiating proteins and fats, as well as fibre from eating more vegetables. It’s easier to reduce calories by filling up on satiating whole foods rich in nutrients and fibre.
Unfortunately, these diets encourage an unhealthy relationship with food by creating a negative association with carbohydrates, fats and other restricted foods. Fad diets fail just as often as they work because of their restrictive nature which leads to feelings of deprivation. People may over consume the “safe” foods, fall off the wagon and binge on forbidden foods, or overeat during the day if they are using the intermittent fasting method.
The Only Way to Lose Weight
The law of thermodynamics tells us weight loss and weight gain are down to calories in and calories out. A consistent calorie deficit over time is the only way to achieve weight loss. And all of the diets mentioned here work by achieving this even if it doesn’t seem obvious.
So, what is a calorie and how does one create a calorie deficit?
A calorie is a unit of energy. Each person uses a certain amount of calories each day to perform basic physiological processes (the processes that keep us alive), as well as other daily tasks like getting dressed, showering, walking and exercising. Each person has their own unique daily calorie requirement depending on gender, height, weight and daily activity level.
If you consume roughly the same amount of calories that your body burns each day you will remain the same weight, and this is called being at calorie maintenance. However, if you consistently consume more calories than you need you will be in a calorie surplus. In this state, you will store this extra energy in the form of fat and perhaps a small amount of muscle (depending on how active you are) and therefore gain weight. While it is much easier to over consume calories from sugary and fatty processed food, people fail to realise a calorie surplus can also occur from eating too much “healthy” food.
In a calorie deficit, you consume less energy than you need and the body has to seek fuel elsewhere. This fuel is most often taken from body fat which results in weight loss over time. Consistently eating fewer calories than you need is the one and only way weight loss occurs.
Scientific studies can confirm this. One study monitored 2 groups of women eating to the same calorie deficit but 1 group on a high sugar diet and the other a low sugar diet. The results showed that both groups of women lost equal amounts of weight (3). Another study found that when people were put in a 30% calorie deficit they lost the same amount of weight independent of the fact that some were on a low-carb/high-fat diet and others were on a high-carb/low-fat diet (4).
A calorie deficit can also occur when you increase your exercise or physical activity. For example, if your calorie maintenance is 2200 calories per day and you increase your activity to burn 400 of those calories, you will be in a 400-calorie deficit. Weight loss will occur if this is kept consistent.
The Bottom Line
If you have had success with one of the diets mentioned here, that’s great! However, you can lose weight in a flexible and balanced way by managing your calories. You don’t have to follow a fad diet and give up your favourite foods completely.
The most important thing to remember when embarking on a weight loss journey is that the best diet for you is one that doesn’t make you feel deprived and is sustainable in the long term.