Top 10 Most Popular Diets

The following diets are covered in this diet review:  

1. Slimming World diet
2. The Atkins diet
3. The GI diet
4. Meal replacements
5. Detox diets
6. Food combining
7. Weight Watchers diet
8. Low fat diet
9. Dietary supplements
10. Rosemary Conley’s Hip and Thigh diet  

1. Slimming World

The theory behind Slimming World

Slimming World used to operate a system whereby there were two ‘plans’ you could follow, called ‘Original days’ and ‘Green days.’ On Green days you were allowed to pick from a large range of foods that were ‘free’ (meaning you could eat unlimited quantities) such as pasta, rice, and some fruits and vegetables.  

On Original days you could have more protein and foods such as fish, lean meat and most fruit and vegetables could be eaten ‘freely.’ In addition there were also ‘syn’ (short for synergy - effectively treats) ratings for certain foods, and depending on how much weight you wanted to lose you would be allowed a specific number of syns per day.  

The method of Slimming World has altered slightly, although the main principle remains the same - you get to chose what you eat, which is known as ‘Food Optimising’.

Now, the method of Slimming World has altered slightly, although the main principle remains the same - you get to chose what you eat, which is known as ‘Food Optimising’. The diet method is also structured around ‘Free Food’, which is intended to satisfy your appetite, and provide thousands of meal ideas for you to make based on this so that you reach your weight loss targets.  

The dietary changes of Slimming World is combined with a regular and unique exercise activity programme, that aims to make members adapt more active lifestyles. Slimming World is also structured around the support you receive every step of the way, either through local group sessions or online.

Pros of Slimming World diet

• Support from a consultant leading the class and the group.
• A structured plan that can help you stick to a low-fat diet.
• A maintenance programme is provided.
• There is little weighing and measuring portions.
• No calorie counting.
• No foods are banned.
• If you are cooking for a family - they can all eat the same foods, there is no need to cook different meals.
• You don’t need to stop after you have reached your weight loss target - the dietary changes are sustainable for life.
• You can still eat out at restaurants without compromising your diet.
• Exercise is an important part of the programme.

Cons of Slimming World diet

• You have to feel ready and want to lose weight, despite the detailed plan; Slimming World cannot make you lose weight.
• The diet plan will aid steady weight loss, so if it’s quick weight loss you’re after, it might not be the best choice.
• You have to follow the ingredients specifically to gain the full benefits of the programme.
• The diet structure can seem confusing and complicated to beginners.

Other dietary information -

Alcohol - Allowed, but as it contains so many calories it will contribute to your daily 'syn' allowance.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes, but coeliacs should always tailor their eating plan to the advice they receive from their dietitian.

Need to buy specialist foods - No.

Restaurant friendly - Yes, but make sure that you are familiar with what you are allowed before dining out.

2. The Atkins Diet

The theory about the Atkins diet

By eating high protein foods (meat, poultry, fish and eggs) and high-fat foods (cream, butter, cheese) you consume fewer calories. Carbohydrates and sugars such as bread, potatoes, rice, chocolate, chips, cereals and sugar are severely restricted.  

The theory of Atkins is that through the low calorie intake, users burn fat stores for energy and therefore see weight loss as a result of this.

The theory of Atkins is that through the low calorie intake, users burn fat stores for energy and therefore see weight loss as a result of this. It is also claimed that advocates will develop steady sugar levels throughout the diet, whereas other dietary methods are high in carbs which can cause fluctuations between blood sugar levels. Through steady fueling throughout the day, Atkin users are also less likely to feel hungry, which is a common vex of many diets.  

There is published evidence to show that many people do lose weight on low-carbohydrate diets such as the Atkins plan, and that weight lost will help blood pressure, blood glucose and cholesterol levels of individuals. The problem is that weight lost by any means (not just on the Atkins plan) will improve all of the health measures already mentioned.

Pros of the Atkins Diet

• Reduces the number of calories consumed and therefore promotes weight loss.
• Weight loss can happen quickly, which can be motivating for users.
• Often a popular diet for men, with the inclusion of red meat and dairy.
• Encourages users to cut most alcohol and processed carbs from their diets.
• The diet can become tedious to the tastebuds after a while.

Cons of the Atkins Diet

• Long-term effects unknown.
• The overall recommendations in this diet are completely different from the recommendations made by registered dietitians for healthy weight loss and healthy lifestyle.
• Nutritionally unbalanced.
• Not suitable for pregnant women, people with kidney disease or gout.
• High saturated (health harming) fat intake.
• Expensive.
• Can cause constipation.
• Long-term maintenance of weight lost would be hard due to the restrictive nature of the plan.
• As the diet is not nutritionally adequate, vitamin and mineral supplements are needed.

Other dietary information -

Alcohol - Not allowed.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes, always adhere to advice given by your registered dietitian.

Need to buy specialist foods - No.

Restaurant friendly - No, you may have to order differently from everyone else.

3. The GI diet

The theory about the GI diet

The Glycaemic Index (GI) ranks carbohydrate food according to how quickly it causes a rise in the blood sugar level. The GI scale runs from 1 to 100, and foods are rated on the spectrum. Glucose for example is 100 on the list and foods with less starch contents are found lower on the spectrum.  

Foods with a lower GI rating slowly release sugar into the blood, therefore providing you with a steady energy supply. In comparison, foods with a high GI content provide quick but short lasting energy supply from the spike in blood sugar levels.  

Low GI foods also help you feel fuller for longer so therefore help you to control your body weight. Research has also suggested that GI diets have a good effect on health i.e. blood fat levels, blood glucose levels and the level of insulin in the blood is more regulated.

Following a GI diet, you will be advised to endeavour to eat foods with a low GI content, as these will make you feel fuller for longer, sustain energy and can maintain blood sugar levels.

Following a GI diet, you will be advised to endeavour to eat foods with a low GI content, as these will make you feel fuller for longer, sustain energy and can maintain blood sugar levels. As a result of this, you are also less likely to eat between meals and this could therefore contribute to weight loss. You will also likely be advised to cut out saturated fats from your diet.

Pros of the GI diet

• A healthy plan that may be maintained in the long term, one of the more sustainable diet plans.
• You are unlikely to feel hungry when following a GI plan.
• You are unlikely to need supplements to complement your nutritional intake on this plan.
• Better control of blood sugar and insulin levels.
• Following the GI diet can help prevent diseases such as diabetes and heart diseases.
• Can increase your energy.

Cons of the GI diet

• You still have to watch portion sizes with this diet as it could be easy to over-consume even low GI foods
• The GI diet only identifies what effect the particular food has on blood sugar levels, ignoring the nutritional information of a whole meal.
• Not all foods which have a low GI are healthy - some of the foods which have a low GI rating are high in things such as saturated fat or salt, but the spectrum does not identify these nutritional downfalls.

Other dietary information -

Alcohol - Allowed

Suitable for vegetarians - Yes.

Suitable for vegans - Yes, it is a very good plan for vegans.

Suitable for coeliacs - Yes.

Need to buy specialist foods - No.

Restaurant friendly - Yes.

4. Meal replacements

The theory about meal replacements

Meal replacements (usually shakes) are designed to replace two meals per day so that you cut back on your total calorie intake and lose weight, e.g. Slim Fast. Usually you have a shake for breakfast and lunch and then have a balanced meal for dinner, usually a 600-calorie meal. Also allowed are two or three low-fat snacks such as fruit, a snack bar or soup.  

Meal replacements are designed to replace two meals per day so that you cut back on your total calorie intake and lose weight.

Meal replacements are intended to help users reduce the number of calories they eat, therefore encouraging the use of fat stores for energy.  

You set yourself a weight loss goal then stay on the two meal replacement options until you have reached your target. Then you can chose to drop to just one meal replacement shake, and incorporate two healthy meals and two low fat snacks into your daily diet.  

Slim Fast specifically works on a 3. 2. 1 principle - three Slim Fast approved snacks, two meal replacement shakes and one sensible meal (usually 600 calories for women and 800 for men). This, combined with drinking two litres of water and regular exercise makes up the main concept of the meal replacement dieting option.

Pros about meal replacements

• An easy way to reduce weight without having to plan and think about meals.
• The products are fortified with many different vitamins and mineral nutrients.
• Meal replacement plans are often simple to follow and don’t involve counting calories.
• Results can happen fairly quickly.
• You can still eat real food during the diet.

Cons about meal replacements

• There is no support for people taking meal replacements.
• There is no education on how to change eating habits in the long term.
• You may grow bored with the range on offer.
• Some of the branded snacks and ready meals are expensive.
• Not all of the meal replacement options are to everyone’s taste.
• They are not a substitute for a long term healthy eating plan.
• Some users have suffered digestion problems as a side effect.

Other dietary information -

Alcohol - Not allowed

Suitable for vegetarians - If you consume milk, then yes. If not then it could be more problematic.

Suitable for vegans - Yes, but contact the manufacturers to clarify which products are suitable.

Suitable for coeliacs - Yes.

Need to buy specialist foods - Yes, there are many products available; shakes, ready meals, soups, snack bars etc.

Restaurant friendly - No, you may feel excluded if going out with friends as it may not fit in with your eating plan. The best way around this would be to save your main meal in the day for the meal out; even so, watch portion sizes and the choice you make as meals out often exceed the 600-calorie meal allowance.

5. Detox diets

The theory about detox diets

Detox diets are based on the theory that our bodies are continually subjected to toxins such as pesticides, food additives, high-fat foods and alcohol. Detoxification is intended to take these toxins out of the body. The length of the diet can vary, but the main food groups included are organic fruit, vegetables, juices, herbal teas, rice and drinking lots and lots of water.  

Detoxification is intended to take toxins out of the body.

Some detox diets involve a period of fasting, others just drinking liquid. Whichever specific variation you choose, it will be a short process, as the diets are low calorie and quite nutritionally poor due to the foods you cut out.  

Eating ‘clean’ is another variation on detox diets and this involves consuming fruit, vegetables, lean protein and whole grains - basically unprocessed foods. This is a more sustainable option in the long run.

Pros about detox diets

• Rapid weight loss.
• May help to increase the amount of fruit and vegetables in the diet.
• Eliminates processed foods, and those high in sugar and fat from the body - which is a positive for your health.
• Low in calories.
• Eating only whole, clean foods helps retain your palate.
• Energy and focus levels can rise as a result of detoxing.

Cons about detox diets

• There is no scientific evidence to suggest that the methods in the diet necessarily rid the body of toxins. This is because the body is intended to repair and detoxify itself.
• Wind may be a problem as detox diets often recommend very high-fiber foods.
• Can get quite repetitive - eating the same foods over and over.
• The weight you lost can be quickly regained once you return to normal food consumption.
• Can lead to imbalances in food groups.
• Detox diets are only a short term fix.
• They are very restrictive.
• There is no advice on how to change eating habits for the long term.
• Rigid structure means it is hard to fit in with everyday living.

Other dietary information -

Alcohol - Not allowed.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes.

Need to buy specialist foods - Yes, as some of the foods recommended may be unfamiliar to you.

Restaurant friendly - No, many restaurants use sugar, salt, additives and canned and packaged food - all of these are banned in detox diets.

6. Food combining

The theory behind food combining

Food combining is the theory that certain foods should not be eaten in the same meal because it interferes with proper digestion. Protein-rich foods such as fish, meat, eggs and dairy products should be consumed separately from carbohydrate rich foods such as bread, rice, pasta, potatoes and sugary foods.  

Food combining is the theory that certain foods should not be eaten in the same meal because it interferes with proper digestion.

It works on the centuries old principle that healthy ecosystems come as result of what food we eat and our digestive systems can benefit greatly from these choices. Meals should be kept simple to allow the body to easily break down and absorb nutrients as foods need different enzymes to complete this function. Otherwise the body can become confused when it has to produce these different enzymes and digestion problems can occur.

Pros of food combining

• Encourages the consumption of more fruit and vegetables.
• In relation to weight loss, the concept of food combining is supposed to stimulate the metabolism - causing the body to burn fat more easily.
• Combining also discourages high fat and sugary foods which could lower the overall calorie content of the diet and thus encourage weight loss.

Cons of food combining

• There is no scientific evidence to prove that we need to separate the foods we eat.
• Some believe the concept is centered around information which is outdated.
• Some plans restrict red meat and dairy foods, so it is important to ensure a balanced diet to allow for these food groups being missed out.
• It can be confusing to remember which foods are supposed to be eaten when and what they can be eaten alongside.
• Can be difficult when you are eating out as many food combining plans encourage cooking from scratch.
• Little advice around increasing physical activity and making permanent changes to eating habits.

Other dietary information -

Alcohol - Allowed.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes.

Need to buy specialist foods - No.

Restaurant friendly - No, you may find it more difficult to eat out if following a food combining programme. This is because many foods are supposed to be cooked from scratch and when dining out it is impossible to tell whether food has been prepared in this way.

7. Weight Watchers diet

The theory behind Weight Watchers diet

Weight Watchers is based on a point system ‘SmartPoints’, which were previously known as ‘Pure points’ or ‘Pro points’. SmartPoints give every food a number of points that are based on the food’s nutritional breakdown. Everyone has a total number of points per day (depending on how much weight you may want to lose), which you can use however you like. No foods are off limits, as long as you remain within your assigned number of SmartPoints. Fruit and vegetables are not subject to points - so you can consume as much as you like of those.  

Weight Watchers is based on a point system ‘SmartPoints’... with dieters having a total number of points per day according to how much weight they want to lose.

Then, through weekly meetings led by a trained specialist - or by learning about the plan online - you will receive information about diets, exercise and healthy lifestyles. You also learn success stories from previous advocates of Weight Watchers to ensure you remain inspired to continue towards your own weight loss targets.

Pros about Weight Watchers diet

• It encourages changes to be made for the long term.
• It is a supportive, group-led environment.
• No foods or drink are banned - you just have to stick to the points you are allowed.
• You can also collect points and use them for a special occasion.
• It encourages slow, sensible weight loss, which is more likely to be maintained.
• Regular recording (writing down) what you eat has proven the best way that most people succeed at losing weight and keeping it off and this method is encouraged at Weight Watchers.
• Portion control is encouraged and comes in use when you stop the programme.
• The groups help to educate members on dietary, lifestyle and healthy eating advice.
• Regular exercise is encouraged through Weight Watchers.

Cons about Weight Watchers diet

• It is a prescriptive diet that some may not be able to stick to forever.
• Counting points may become an obsession and the relative health merits of certain foods may be overlooked.
• Some people don’t like to measure their weight loss progress on a weekly basis and can find this de-motivating.
• It is possible to use all of the points on unhealthy foods - which will not help with weight loss goals or overall health.
• Working out points can be confusing for beginners.
• Buying Weight Watchers branded foods can prove quite expensive.

Other dietary information -

Alcohol - Allowed.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes.

Need to buy specialist foods - No.

Restaurant friendly - Yes.

8. Low fat diet

The theory about a low fat diet

All fats are very high in calories and therefore low fat plans aim to drastically reduce the amount of fat individuals eat. Foods such as butter, oil, margarine, mayonnaise, chips, chocolate and cheese are limited. All of these foods are replaced with lower-fat versions where possible, and if that is not possible then they are severely restricted.  

Low fat plans aim to drastically reduce the amount of fat individuals eat.

However, cutting fatty foods alone from your diet will not lead to weight loss, the number of calories you consume must also be reduced and exercise introduced to maintain a healthy diet and weight. The body also needs fat to function correctly. Good fats (found in oily fish, nuts, plant foods and avocados) are required to: help skin health, heart health, the absorption of vitamins and to provide the body with energy.

A low fat diet is a very good start towards eating healthily and losing weight however, balance must be kept in mind, as many foods that are low in fat are either high in salt (savory foods) or high in sugar (sweet/dessert foods). All food contains calories and this must be remembered even when eating low-fat foods.

Pros of a low fat diet

• Cutting back on fat can help reduce the number of calories you eat and therefore help weight loss.
• Consumption of fruit and vegetables is encouraged as both are low in fat.
• Can help ward off heart disease and high cholesterol levels.
• Can lower blood pressure.

Cons of a low fat diet

• High-sugar foods may be eaten to excess on a low fat diet as sweets are low in fat and this can be detrimental to the health of the teeth.
• Be aware that it is important to read labels on foods, just because a food is low in fat does not necessarily mean that it is low in calories.
• A proportion of fat is still needed in a healthy diet, to give your body energy and to aid the absorption of certain vitamins and minerals.

Other dietary information -

Alcohol - Some types are allowed, but drinks such as Irish cream liqueur and some cocktails are not allowed.

Suitable for vegetarians - Yes.

Suitable for vegans - Yes.

Suitable for coeliacs - Yes.

Need to buy specialist foods - No.

Restaurant friendly - Yes, but always ask the waiting staff to check how foods are cooked.

9. Dietary supplements

The theory about dietary supplements

There are many different types of supplements marketed towards those people who want to lose weight. Dietary supplements come in different forms including: capsules, tablets, liquids, powders, bars and even tea bags, all of which make varying claims. Many boast that they will do things such as ‘will burn fat’, ‘boost your metabolism’ or ‘help curb your appetite’. It is important to read the ingredients list and also the accompanying literature as many supplements only claim to work ‘if combined with a calorie-controlled diet and exercise’. Always treat any radical claim with caution, if it sounds too good to be true, it probably is!  

Dietary supplements come in different forms including: capsules, tablets, liquids, powders, bars and even tea bags, all of which make varying claims.

There are no magic ways to lose weight unfortunately, and many people mistakenly believe many of the unfounded claims that supplements make. Particularly if you are already taking prescribed medication, always check with your doctor to see if the dietary supplements will interfere with the medicine in any way.

Pros of dietary supplements

• Short term use of dietary supplements can give some people the extra mental push they need to start their weight loss journey.

Cons of dietary supplements

• You should not take supplements if you are pregnant or breastfeeding; always read the label and ask your doctor if in doubt.
• Many supplements make unfounded claims that are not true; always be skeptical about any claim made.
• They must always be taken with a calorie-controlled diet and physical activity - maybe just the diet and physical activity would be a good place to start.
• They can be really expensive, a better idea would be to look at the food you eat and spend more on the ‘healthy’ foods such as fruit and vegetables and starchy foods.
• Certain dietary supplements have been found to have side effects, always do your research before you start taking any supplements.

Other dietary information -

Alcohol - Depends on the supplement; always read the label.

Suitable for vegetarians - Depends on the supplement; always read the label.

Suitable for vegans - Depends on the supplement; always read the label.

Suitable for coeliacs - Depends on the supplement; always read the label.

Need to buy specialist foods - Yes, depends on the supplement; always read the label.

Restaurant friendly - Yes.

10. Rosemary Conley’s Hip and Thigh diet

The theory behind Rosemary Conley's Hip and Thigh diet

This diet is a close comparison to the guidance for a healthy diet, being low in fat. Foods that are encouraged are fruit and vegetables, starchy foods and smaller amounts of low-fat milk and dairy products and low-fat meats. A sensible pattern of eating is promoted i.e. three meals per day, with low-fat snacks between. One of the best things that Rosemary Conley promotes is exercise; her plan is unique in this respect.  

As the name of this diet suggest, it is intended to target the hip and thighs, both problematic areas for people looking to lose weight...

Unlike others, this diet plan includes carbohydrates, which when eaten in moderation, Conley’s plan believes will makes you feel fuller for longer. Originally developed in 1983, as the name of this diet suggests, it is intended to target the hip and thighs, both problematic areas for people looking to lose weight. Conley’s hip and thigh diet includes recipes, information about exercise and information on how to maintain your weight once you have reached your weight loss goal.  

Getting into the habit of eating a low fat diet may take a while but you are unlikely to be hungry and if it means increasing the amount of the ‘healthy foods’ in your diet then it must be good news. Rosemary Conley’s own personal story provides inspiration for those looking to lose weight themselves and the programme also values previous success stories to provide motivation along the way.

Pros of Rosemary Conley's Hip and Thigh diet

• A filling diet, you are unlikely to be hungry on this plan.
• Encourages eating regularly.
• Encourages taking regular activity to help weight loss.
• Exercises are specifically designed to target the hips and thighs.
• Includes information on how to plan meals in advance, which can prove difficult with other diets.

Cons of Rosemary Conley's Hip and Thigh diet

• May actually be too low in fat, if followed strictly.
• You may over-eat sugar, this is common when sticking to a low fat diet.
• Research has found that you can