“Sorry, I can’t eat cake I’m on a diet”
By definition, a “diet” is the sum of energy and nutrients obtained from foods and beverages consumed regularly by individuals. To put it in simple terms, it is what you eat and drink on a day to day basis. Somewhere along the way, the meaning shifted to something more specific. Something that people dread. You guessed it right – Weight loss.
As a generation, we are used to quick results. Everything from groceries to electronics can be bought with a click. Unintentionally (or not) we have begun to channel that into how our bodies respond to an external stimulus, such as food and exercise. We expect results within a short span of time and will go to great lengths to ensure that it happens! Ever completely cut off a food group or had just juices for a week to shed some weight? That is exactly what I’m talking about.
This is what we call a ‘fad diet’. It’s nothing but a trend that claims to guarantee rapid weight loss and have an upper hand over our perfectly normal balanced diet. Most of the claims around fad diets might seem appealing.
“Guaranteed weight loss in a week!”
“Helps in removing harmful toxins from your body”
“Carbohydrates are stored as fat. Switch to fat as your primary source of energy.”
Sounds familiar? Although these claims might seem appealing, the diet by itself is extremely restrictive. Every single nutrient has a role to play in our body and nothing in isolation is inherently bad. Any ‘diet’ that you choose to follow is completely based on individual preference. But, is it sustainable? Is it personalised to help achieve your goals? It is imperative that everyone is informed of the pros and cons of these diets and make an informed choice. For that reason, here is a compilation of the most popular diets:
(1) Ketogenic diet: Both carbohydrates and fat can be used as a source of energy by the body. The body relies on glucose (broken down from carbohydrates) when one consumes their normal diet (1). In the complete absence or reduced amount (<20g) of carbohydrates in the body, the body enters a state of ketosis, wherein it relies entirely on stored fat for energy. Signs of ketosis can be identified by increased ketone bodies in the blood, headaches and fatigue due to extremely low carbohydrate intake and bad breath. Breakdown of fat results in the rise of ketone bodies in the blood, which are used as an alternate source of fuel. The ketogenic diet involves consuming minimal to no carbohydrates (~5% from diet) and using fat (~75% from diet) as a source of energy. It encourages consumption of copious amounts of fat from sources like bacon, ghee,butter,nuts,cheese etc. Starch, grains, beans and legumes, fruit and starchy vegetables are avoided. The sources of fat usually consumed in a keto diet are low chain triglycerides (LCT’s). Off late, consumption of fat sources that contain Medium Chain Triglycerides (MCT’s) like coconut oil are observed. Although they do not contain concentrated amounts of MCT’s, it is suggested that MCT’s generate more ketone bodies and may be more beneficial to incorporate in a keto diet (1).
Pros: A ketogenic diet was developed for children diagnosed with epilepsy. It was said to be therapeutic as fats do not spike insulin. It works by stabilising various mechanisms related to synaptic functions and thus has an anti-seizure effect. So you know who it actually benefits (2). Although, consumption of high amounts of fats can induce better satiety (3), thus reducing food consumption in subsequent meals. This can potentially help in losing weight. In order to adapt a ketogenic diet to the current lifestyles and improve adherence, a cyclical keto diet came into the picture. This involves following a keto diet for 4-5 days and increase carb intake for 1-3 days. There is currently no evidence to support the validity of a cyclical ketogenic diet.
Cons: A ketogenic diet can be extremely restrictive. Cutting all sources of carbohydrates can lead to irritability, ‘brain fog’, mood swings, headache and even constipation, due to lack of fibre in the diet. Although it might result in weight loss (provided you’re in a caloric deficit), it may not be sustainable in the long run. I mean, how long are you going to stay away from a good slice of pizza? On a more serious note, the exclusion of whole grains, fruits and vegetables could lead to deficiencies of B vitamins, iron, zinc etc. Further, the long term effects of such a high fat diet haven’t been studied.

(2) Paleo Diet: The Paleolithic diet or paleo diet resembles what hunters or cavemen ate several years ago. This diet primarily revolves around what our ancestors had access to – Whole foods. And by that, I literally mean, whole foods only. Sounds easy? Not really. You see, cavemen didn’t cultivate their food. So what they ate was what they could find. So on this diet, the idea is to avoid anything that could be made in a factory. What this diet would comprise of would be meat, free range eggs, fruits, vegetables, nuts and seeds. In order to adapt it to the current scenario, consuming spices/condiments and olive/coconut oil are acceptable. It has been speculated that they did have access to grains. However, evidence for a paleo diet to be superior than a balanced diet is still in question (4).
Pros: Any food that is ‘processed’ such as aerated beverages, most dairy products, legumes/beans, vegetable oils and even grains are not to be consumed on this diet. Since you will be consuming an abundance of fruits and vegetables, there lies an advantage. The focus on whole foods does steer us away from a conventional diet primarily filled with calorie dense foods of low nutrient content. In fact, studies have shown that a paleo diet improves insulin sensitivity, blood pressure and cholesterol (5).
Cons: To start with, the diet is pretty restrictive. More than it, it also creates a list of ‘good food’ and ‘bad food’. That by itself creates a sense of fear of food and is problematic. Further, we can follow a perfectly wise diet even with the inclusion of dairy, starch and legumes. The exclusion of dairy might lead to a deficiency in calcium(4).
(3) Detox diet: A detox diet is used to eliminate toxins from the body and assist with weight loss. These are also commonly known as juice cleanses. However, it can also involve consuming vitamins, minerals, laxatives and other ‘cleansing foods’ (6). While most commercial detox diets do not specify the ‘toxins’ they claim to remove, it should be noted here that the dose of the said toxin determines its harmfulness (7). For example, even an essential mineral like Iodine when present in excess can lead to thyroid disorder. Does that mean iodine in isolation is a toxin?
Various organs in our body, and in specific the liver are involved in eliminating potential toxins from the body. Commercial detox diets lure the masses promising rapid weight loss, but there is no scientific evidence to support this claim.
Pros: Well. This is a tough one. In a recent review on detox diets (7), it was highlighted that some plant based foods like coriander, citric acid (found in citrus fruits) and malic acid (found in grapes) can help in removing toxic metals from the body. However, most of these studies were performed on animals and can’t be generalised to the human population. While these detox diets may be successful in inducing weight loss in the short term, they may not be sustainable in the long run.
Cons: Detox diets involve severe energy restriction and might lead to nutrient deficiencies. For example, by just drinking juices for a week, one may not meet their recommended protein intake! Further, detox dieters could potentially be over consuming supplements/laxatives (7). A variety of nutrients need to be consumed on a daily basis, which a detox diet may not be able to provide.
(4) GM diet: A diet that was initially created for the employee of General Motors (GM), the GM diet allows you to eat a certain combination of foods each day. For example, on day one you eat only fruit (except bananas). On day two, only vegetables. This pattern of consuming specific foods continues for a period of 7 days. Since fruits, vegetables and other items allowed in the diet are low calorie, it has been shown to induce weight loss. However, as much as it is popular, there isn’t any research to support the claims of this diet.
Pros: Although a GM diet does include some whole foods, it follows a restrictive and specific pattern.
Cons: We need a variety of nutrients on a daily basis. By consuming just fruits throughout the day, other nutrients such as protein, fat and several other micronutrients available in whole grains, fruits and vegetables are neglected. Moreover, tendency to feel hungry might be prevalent. The weight lost on a GM diet may be temporary. Since it isn’t something you can follow lifelong (fight me!), there lies a possibility of regaining the weight lost.
Do you sense a pattern with all these diets? All of these diets involve restricting either all your food or a specific food/food group. Do you think that’s sustainable and that you can follow it life long? Not really right? In an ideal scenario, for a diet to be sustainable, it needs to be personalised to suit you and your goals. There isn’t one specific diet that is applicable to everyone. As mentioned before, all nutrients play a specific role in your body. Completely cutting yourself off from one for the sake of losing weight does more harm than good. Always make an informed decision when it comes to your fitness goals. The shortcuts might seem tempting, but remember health is wealth.

References:

1) Walcyzk, T, Wick, JY. The ketogenic diet: making a comeback. The Consultant Pharmacist. 2017; 32(7), 388-396.
2) Rho, JM. How does the ketogenic diet induce anti-seizure effects? Neuroscience Letters. 2017; 637, 4-10
3) Paoli, A. Ketogenic diet for obesity: Friend or foe?. International Journal of Environmental Research and Public Health. 2014; 11(2),2092-1207.
4) Pitt, CE. Cutting through the Paleo hype: The evidence for the Paleolithic diet. Australian Family Physician. 2016; 45(1): 35-38.
5) Tarantino, G, Citro, V and Finelli, C. Hype or Reality: Should Patients with Metabolic Syndrome-related NAFLD be on the Hunter-Gatherer (Paleo) Diet to Decrease Morbidity?.Journal of Gastrointestinal and Liver disease. 2015; 24(3): 359-368.
6) Allen, J, Montalto, M, Lovejoy, J, Weber, W. Detoxification in naturopathic medicine: a survey. Journal of Alternative and Complementary Medicine. 2011;17(12):1175-1180.
7) Klein, AV, Hiat, H. Detox diets for toxin elimination and weight management: a critical review of the evidence. Journal of Human Nutrition and Dietetics. 2014; 28(6): 675-686.
8) Healthline. What is the Cyclical Ketogenic Diet? Everything you need to know.
9) Medical News Today. What are the signs of ketosis?
10) Harvard T.H. Chan School of Public Health. Diet Review: Ketogenic Diet for weight loss.
11) Masharani, U, Sherchan, P, Schloetter, M, Stratford, S, Xiao, A, Sebastian, A, Nolte Kennedy, M and Frassetto, L. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition.2015; 69(8), 944-948.
12) Harvard T.H. Chan School of Public Health. Diet Review: Paleo diet for weight loss.
13) Precision Nutrition. The Paleo problem.