Diet Plans & You

Whether it’s the celeb-endorsed keto, to the healthy DASH, which diet plan is right for you? Dr Renuka David picks the most popular diets of the season, listing out the pros and cons of each.

5:2 Diet

The 5:2 diet is based on a principle known as intermittent fasting (IF), where you eat normally for 5 days a week and fast on the other two.


  1. Sticking to a regimen for 2 days a week can be more achievable than 7 days, so you may be more likely to persevere with this way of eating and successfully lose weight.
  2. Two days a week on a restricted diet can lead to greater reductions in body fat, insulin resistance and other chronic diseases.


  1. The non-restricted days don’t mean unlimited feasting. While you don’t need to be as strict about your calorie consumption, you still need to make healthy choices and be physically active.
  2. There’s a risk that your restricted eating days may not be nutritionally balanced. Skipping meals could make you feel dizzy, irritable, give you headaches, and make it hard to concentrate, which can affect work and other daily tasks.
  3. Other reported side effects are difficulties sleeping and daytime sleepiness, bad breath and dehydration.

Takeaway: The 5:2 is a simple way to reduce calorie intake. There are lots of versions of this diet, with some being less safe than others. If you choose to follow this diet, choose an evidence-backed plan based on healthy, balanced eating and written by a dietitian. It’s vital for your health to avoid nutritional deficiencies, dehydration and overeating on non-fasting days.

Never attempt to delay or skip meals if you’re pregnant, have had or are prone to eating disorders, or have diabetes.

Dukan Diet

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The Dukan diet is a low-carb, high-protein diet. There’s no limit to how much you can eat during the plan’s 4 phases, provided you stick to the rules of the plan.

During phase 1 (an average of 5 days), you’re on a strict lean protein diet with low-fat, protein-rich foods such as chicken, turkey, eggs, fish and fat-free dairy. Carbs are off limits, except for a small amount of oat bran. Vegetables and fats are banned. The next 3 phases of the plan see the gradual introduction of some fruit, veg and carbs, and eventually all foods.

The aim is gradual weight loss and long-term weight management. There’s no time limit to the final phase, which involves having a protein-only day once a week and doing regular exercise.


  1. You can lose weight very quickly, which can be motivating. It’s a very strict and prescriptive diet, which some people like. It’s easy to follow, and you don’t need to weigh food or count calories.
  2. Apart from keeping to low-fat, low-salt and high-protein foods, there’s no restriction on how much you can eat during your first 2 weeks.


  1. At the start of the diet, you may experience side effects such as bad breath, a dry mouth, tiredness, dizziness, insomnia and nausea from cutting out carbs.
  2. The lack of wholegrains, fruit and veg in the early stages of the diet could cause problems such as constipation.

Takeaway: Rapid weight loss can be motivating, but it’s unsustainable and unhealthy. The Dukan diet isn’t nutritionally balanced, which is acknowledged by the fact you need a vitamin supplement and a fibre top-up in the form of oat bran. There’s a danger this type of diet could increase your risk of long-term health problems if you don’t stick to the rules. The diet lacks variety in the initial phases, so there’s a risk you’ll get bored quickly and give up.

Paleo Diet

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The paleo diet, also known as the caveman diet, consists of foods that can be hunted and fished (such as meat and seafood) or gathered (such as eggs, nuts, seeds, fruits, vegetables, herbs and spices). It’s a regime based on the supposed eating habits of our hunter-gatherer ancestors during the Paleolithic era, before the development of agriculture, around 10,000 years ago.

That means cereal grains including wheat, dairy, refined sugar, potatoes – as well as anything processed or with added salt – are strictly off the menu. It is generally seen as a low-carb, high-protein diet, with some variations on carbohydrate and meat intake.


  1. The paleo diet encourages you to eat less processed food, less high-fat and high-sugar foods (such as cakes, biscuits, crisps), and more fruit and vegetables.
  2. Reducing your consumption of high-calorie foods will reduce your calorie intake and help you lose weight.
  3. The diet is simple and doesn’t involve calorie counting. Some plans are more flexible, which can make the diet easier to stick to and increase your chances of success.
  4. Advocates say the paleo diet is a long-term healthy eating plan that can help you lose weight and reduce your risk of diabetes, heart disease, cancer and other health problems.


  1. There are no accurate records of the diet of our Stone Age ancestors, so the paleo diet is largely based on educated guesses, and its health claims lack any scientific evidence.
  2. Most versions of the diet encourage eating a lot of meat, which runs counter to other advice on meat consumption.
  3. Many versions ban dairy products and whole grains, which are part of a balanced diet. Unless it’s for a medical reason, there’s no need to cut out whole food groups from your diet.
  4. Cutting out food groups without careful substitution can lead to nutritional deficiencies.
  5. The paleo diet can be expensive. For example, it advocates eating only grass-fed meat.

Takeaway: Most versions of the paleo diet exclude key food groups, raising the potential for nutritional deficiencies unless careful substitutions are made, and dietary supplements may be necessary. The diet has some positive aspects, so an adapted version that doesn’t ban any food groups – such as whole grains, dairy and legumes – would be a better choice. The diet lacks variety, so there’s a risk you’ll get bored quickly and give up. If you want to copy your paleolithic ancestors, you’re better off mimicking their activity levels rather than their alleged diet.

Alkaline Diet

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The alkaline diet is based on the idea that modern diets cause our body to produce too much acid. The theory is that excess acid in the body is turned into fat, leading to weight gain. High acidity levels have also been blamed on conditions such as arthritis, osteoporosis, tiredness, and kidney and liver disorders. There is, however, no scientific evidence for this. The diet involves cutting back on acid-producing foods such as meat, wheat and other grains, refined sugar, dairy products, caffeine, alcohol and processed foods in favour of ‘alkaline foods’, which reduce the body’s acidity levels. This translates into plenty of fruit and vegetables.


  1. The diet contains plenty of good healthy eating advice, such as cutting down on meat, avoiding sugar, alcohol and processed foods, and eating more fruit and veg, nuts, seeds and legumes.
  2. This means you’ll be cutting out foods you may normally eat and replacing them with healthier choices, which will also reduce your calorie intake.


  1. Your body regulates its acidity levels, regardless of diet. When cutting down on dairy products such as milk, cheese and yoghurt, you need to find other calcium substitutes, as cutting out an entire food group is never a good idea.
  2. Getting to grips with what you can and can’t eat on the diet can be time-consuming, particularly in the beginning.

Takeaway: The theory of the alkaline diet is that eating certain foods can help maintain the body’s ideal acidity levels to improve overall health. The diet is not supported by any evidence. Any weight loss is likely to be because you are being careful about what you are eating, reducing high-fat and high-sugar foods as well as overall calories.


Photo: Alexander Mills / Unsplash

The Dietary Approaches to Stop Hypertension (DASH) diet is an eating plan based on plenty of fresh fruits and vegetables, as well as lean proteins, low-fat dairy, beans, nuts, and vegetable oils, while limiting sweets and foods high in saturated fats. Those who follow the DASH diet have a significantly lower risk of hypertension and heart failure. In addition, a low-sodium modification to the DASH diet is effective in lowering blood pressure.


  1. The DASH diet has been studied extensively and comes with evidence-based health benefits to not only curb hypertension and heart problems, but also prevent cholesterol and type 2 diabetes.
  2. The food recommended on the DASH diet is accessible, found almost anywhere. There are no specific hard-to-find or expensive ingredients.
  3. Diet plans are flexible and available for various calorie levels based on your activity and body’s needs.
  4. The DASH diet stays within nutritional guidelines, unlike most other diets which cause the macronutrient balance to shift.
  5. This is a long-term and sustainable diet plan, designed to be a lifestyle that you can maintain for life.


  1. Convenience and packaged foods aren’t a part of this plan, due to the high sodium content that is usually present in them. The diet’s focus is fresh foods.
  2. Since there is no calorie counting or portion control involved in the DASH diet, you run the risk of binge-eating. Be aware and keep tabs on your serving sizes.
  3. It isn’t specifically designed for weight loss – the focus is on health.

Takeaway: The DASH diet is great for people who want to keep heart disease, blood pressure and other lifestyle-related ailments at bay. While most healthy people can follow it without problems, people with kidney or liver problems, and those on medications should consult their doctors and nutritionists before getting on the diet.

Vegan Diet

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A vegan diet contains only plant-based foods (such as vegetables, grains, nuts and fruits) and foods made from plants. Vegans do not eat foods that come from animals, including dairy products, eggs and in some cases – even honey! For a healthy vegan diet, eat at least 5 portions of a variety of fruit and vegetables every day, use wholegrains, opt for soy, oat or nut milks and yoghurts, get your proteins in beans and pulses, and drink plenty of fluids. Good sources of calcium and iron for vegans include green, leafy vegetables, calcium-set tofu, sesame seeds and tahini, pulses and dried fruit, such as raisins, prunes, figs and dried apricots. Good sources of vitamin D for vegans (other than sunlight exposure!) include fortified fat spreads, breakfast cereals and unsweetened soya drinks, as well as supplements. For omega 3 acids, typically found in fish, vegans should opt for walnuts, flaxseed (linseed) oil or rapeseed oil and even tofu.


  1. When you eat the right foods, a vegan diet is high in fibre, vitamin C, magnesium, iron and lower in saturated fats and calories.
  2. Vegans are at lower risk of cardiovascular diseases, obesity and type 2 diabetes.
  3. A vegan diet is considered better for the environment and the planet, due to the impact of animal farming practices. It is also considered a cruelty-free diet.


  1. Since your source of nutrition is only healthy, plant-based foods, there might be limited choices and it is restrictive.
  2. There could be possible nutritional deficiencies with calcium, vitamin B12, omega 3 fatty acids and protein. Ensure your diet has all of this, and include supplements if need be.
  3. You’ll need to stay on top of nutritional labels – watch out for seemingly plant-based foods that could contain gelatin, whey or casein. Also, dining out at people’s homes and restaurants might be a challenge. It is advisable to do your research before you head out.

Takeaway: While consuming a vegan diet is likely to produce health benefits and a healthier weight, it is not a guarantee. For example, if you are trying to slim down, you still need to be mindful of the foods you choose and the amount you eat. There is also an increasing number of heavily processed vegan foods. Many times, these foods are just as unhealthy—containing more fat and calories—as their traditional counterparts. Healthier vegan diets result in a substantially lower risk for heart disease, whereas the less healthy vegan diet is associated with a higher risk.

Ketogenic Diet

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A ketogenic diet—also called a keto diet—is a very low carbohydrate diet designed to force your body to burn fat instead of glucose for energy. In essence, it is a diet that causes the body to release ketones into the bloodstream. Most cells prefer to use blood sugar, which comes from carbohydrates, as the body’s main source of energy. In the absence of circulating blood sugar from food, we start breaking down stored fat into molecules called ketone bodies (the process is called ketosis). Because it lacks carbohydrates, itis rich in proteins and fats. It typically includes plenty of meats, eggs, cheeses, fish, nuts, butter, healthy oils, seeds, and fibrous vegetables. The breakup is 75 percent fats, 20 percent proteins and 5 percent carbs.


  1. Aa ketogenic diet reduces seizures in children, sometimes as effectively as medication. Because of these neuroprotective effects, questions have been raised about the possible benefits for other brain disorders such as Alzheimer’s, Parkinsons, multiple sclerosis, sleep disorders, autism, and even brain cancer.
  2. Weight loss is the primary reason my patients use the ketogenic diet. Previous research shows good evidence of a faster weight loss when patients go on a ketogenic or very low carbohydrate diet.
  3. A ketogenic diet also has been shown to improve blood sugar control for patients with type 2 diabetes, at least in the short term. There is even more controversy when we consider the effect on cholesterol levels. A few studies show some patients have increase in cholesterol levels in the beginning, only to see cholesterol fall a few months later.
  4. According to research, keto diets may help athletes control body weight, reduce body fat, and maintain muscle mass in weight-sensitive sports. In some situations, it appears that endurance athletes adapt to keto diets and are able to burn fat more efficiently than their high-carb, low-fat diet counterparts.


  1. The ketogenic diet is highly restrictive, since it avoids most whole grains and grain products, beans, legumes, fruits, starchy vegetables and all sugars. Certain milk products are also eliminated.
  2. Enjoying a piece of cake at your child’s birthday or grabbing a granola bar before a long flight would quickly kick yourself out of ketosis. As a result, your body would begin burning glucose for fuel instead of fat. So you can’t allow yourself even the occasional cheat.
  3. The transition into ketosis may trigger side effects, referred to as the keto flu, that may last up to a few weeks, including fatigue, weakness, light-headedness, insomnia, headaches, mild irritability, gastrointestinal symptoms, nausea and exercise intolerance.
  4. The keto diet eliminates essential nutrients such as fiber, vitamin C, calcium and vitamin D. For this reason, many nutrition and healthcare professionals recommend working with a healthcare professional to make sure you are getting the nutrition you need.
  5. Ingredients might be expensive. While some people who are interested in the diet look forward to eating bacon and butter, those foods are high in saturated fat. Healthier versions of the diet recommend foods such as coconut oil, avocado, raw, unsalted nuts and other plant-based fats.

Takeaway: While the ketogenic diet may be effective for rapid weight loss, it is unknown if the eating plan is the most effective way to help you maintain a healthy weight for the long-term. But it is hard to follow, and “yo-yo diets” that lead to rapid weight loss fluctuation are associated with increased mortality. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.

Mediterranean Diet

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This is based on the traditional foods eaten by people living in the Mediterranean region, especially Greece. It’s loaded with nutrient-dense choices, with an emphasis on vegetables, fruits, whole grains, legumes, nuts and seeds, eggs, dairy, fish, and olive oil. Research suggests following this diet may help reduce your risk of heart disease, cancer, diabetes, and other health concerns. There are not many off-limits foods on the Mediterranean diet. All food groups are encouraged, with a few additional stipulations. That said, even foods like red meat, red wine and added sugar are fine to include occasionally.


  1. The Mediterranean diet does not eliminate any food groups and encourages a variety of nutrient-dense foods, making it easy to meet your nutritional needs and enjoy a wide range of foods and flavors.
  2. A Mediterranean diet is associated with reduced risk of coronary heart disease, heart attack, and overall mortality. It may help those with type 2 diabetes achieve better blood sugar control.
  3. Improved mental health is a surprising benefit. A 2018 study in Molecular Psychiatry found that those most closely following a Mediterranean diet were 33 percent less likely to develop incident depression than those not following a Mediterranean diet.
  4. Satiating fats like olive oil and nuts, in conjunction with the many fiber-rich vegetables and fruits recommended—can help you feel full longer and promote weight loss.
  5. A meta-analysis found that those who adhered most closely to the Mediterranean diet had a lower risk of developing colorectal cancer, breast cancer, gastric cancer, liver cancer, head and neck cancer, and prostate cancer.


  1. The costs of some foods like good quality fresh fish, seeds, nuts, and olive oil could be a deterrent.
  2. There are concerns about the allowance of red meat and alcohol intake allowed in this diet.
  3. The possibility of reduced calcium and vitamin D due to lesser dairy is a concern, and needs to be addressed.
  4. There are no specific guidelines for calorie counts, portion sizes, or strict foods to avoid, which makes it easier to lapse.

Takeaway: When searching for the right diet, it’s important to choose something that works for your lifestyle, that promotes good health, and that’s feasible to stick to long-term. The Mediterranean diet is a well-researched eating plan that may check off these criteria for many people, and includes all 5 food groups. Just be careful to watch your portions!

Content Sources: NHS / Harvard Medical School / Verywellfit

Consult Dr. Renuka