I know I'm not the only one who's tried like a million diets in the past; and who knows, maybe you're still trying to find one that works for you, or perhaps you're happily following a plan that makes you feel fantastic. The UK diet industry is worth over £2 billion and it's no wonder it's such a huge business with so many of us spending money on its shakes, pills, branded food and programmes. But remember, it's important to think about the pros and cons of anything you're thinking of embarking (and spending money) on. That's why I'm giving you a complete, unbiased rundown of the most popular diets that you might be thinking of investing in...

Slimming World

This plan's core concept is to swap high-fat foods for low-fat choices. It works by creating a calorie deficit and encourages increasing the amount of exercise followers do. There's no calorie counting, and no banned foods. In fact, there's a lengthy list of 'Free Foods' which can be eaten in unlimited amounts, including super healthy vegetables, lean meat, fish and eggs. The weekly group support and weigh in meetings help you keep motivated and accountable. Sounds great so far!

However, there are some negatives. Slimming World doesn't educate on calories or portion sizes, so it can be tough to stick to when you come off the programme; you could well put the weight back on. Some of the 'Free Foods' are certainly less than healthy in unlimited amounts, like pasta, potatoes and low-fat yoghurts. It's definitely an encouraging thing to have regular weigh ins to keep you on track and determined to do well, but this plan is only concerned with weight loss. If you lose weight that week then great, but if not, that's a failure. As we all know, weight loss isn't the be all and end all, but at Slimming World, it is. This places an unhealthy focus on the number on the scales and not the dieters' overall health or wellbeing.

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5:2 Diet

This one is based on the concept of intermittent fasting where you eat normally for 5 days a week and 'fast' on the other 2 days. A huge calorie deficit on the fasting days (where you only consume 500-600 calories throughout the whole day) makes your body turn elsewhere for energy; first glucose and glycogen, and then finally your fat stores. The 5:2 diet reduces your calorie intake over the week due to the two days of very low calorie consumption and is easy to stick to as it's only strict for two out of seven days, which isn't too difficult. Skipping meals on the fast days could make you feel dizzy, sick and irritable, and could cause headaches and a lack of concentration. And you can't go completely off the wagon on the other 5 days, it's important to eat healthily, not only to keep the calories down but to also ensure you're not getting dehydrated and lacking vital nutrients. Another issue is that it is not suitable for diabetics or pregnant women, or if you've suffered with eating disorders in the past.


WeightWatchers gives a point value to foods based on their protein, carbohydrate, fat and fibre content. Basically, it's a calorie-controlled diet that allows you to make up your daily food intake by counting up the points in each serving, so it's flexible and super easy to follow. Like Slimming World, fruit and veg are 'free' foods, no foods are banned, and there's weekly meetings to weigh you in and keep you on track. Another bonus is that you also get a 'safety net' each week of points which you can save up for a special occasion, meal out or a few treats.

Again like Slimming World, it's only concerned with weight loss and it doesn't teach you about what calories are actually in foods, so as soon as you come off the plan you could struggle to stick to a controlled diet. The WeightWatchers branded food is encouraged on the plan as they're point-controlled but again, they're often high in sugar (but lower in fat, hence the lower calories) and artificial ingredients, and not actually that healthy.

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The concept of the Atkins diet is to be high in protein and fat, and low in carbohydrates to keep your blood sugar level consistent and help you lose weight quickly. It's great for people who like to eat lots of good food and who hate counting calories; in the first phase all you need to worry about is eating loads of protein, as much fat as you want and strictly limiting your carbs. You'll tend to drop the pounds quickly on this diet which is motivating, and it cuts out processed foods (carbs and alcohol in particular) whilst focussing on protein and veg. There are quite a few side effects though; bad breath, tiredness, dizziness, insomnia, nausea and constipation to name a few. It also doesn't take into account the high amount of red meat and saturated fat you're likely to eat (which goes against general medical advice). Once you start eating carbs again, it's common to see the weight creep back on.


This diet plan is aimed at people with a BMI of 25 and over (considered as overweight) and focusses on a low-calorie plan that replaces meals with SlimFast shakes, bars and branded snacks. The idea is that you have one regular (but calorie-controlled) meal a day, and then have two meal replacement shakes or bars along with a couple of recommended snacks. It's good for people on the go as the pre-prepared snacks/shakes are convenient and easy, and the diet plan is easy to follow. However... Meal replacement diets don't educate the follower on calories in real foods, portion control and their normal eating habits. The branded products are supposed to make up around 70% of the daily calorie intake, but these can be expensive and so if you're on a budget this will get tricky. The meal replacement products and snacks are generally high in sugar, lower in protein and full of artificial ingredients, and if you're not keen on the taste you're pretty much screwed. Again, like so many of the diets here, Slim-Fast can be good for kick-starting weight loss but it can be tough to stick to and you could well put the weight back on as soon as you start eating normally.

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Paleo (Caveman) Diet

The Paleo diet focusses on meat, seafood, eggs, nuts, seeds, vegetables, fruit and herbs/spices, mimicking our hunter-gatherer ancestors' diet. Because you can only eat foods that can be hunted or gathered, grains and all processed foods are simply not an option. It's high in fat and protein, and low in carbohydrate, which will stabilise your blood sugar levels and in theory keep you fuller for longer, whilst encouraging your body to burn fat for energy. It's clearly a good thing in that you're encouraged to eat only natural foods and no processed or sugary goods, along with plenty of vegetables and fruit.
The Paleo diet is fairly simple to follow but it can be tricky for people who are pushed on time, as it involves preparing most meals from scratch. It's also pretty much a no-go for vegetarians as you need meat, seafood and eggs to make up much of the diet. Similarly to the Atkins diet, following this plan could lead to nutritional deficiencies, headaches and dizziness as your body gets used to the lack of carbs, and it's really important to eat plenty of fruit and veg to ensure you're getting enough fibre for good digestion. It can be expensive to follow over a longer time period too, as good-quality cuts of meat and plenty of nuts and seafood aren't cheap.

Alkaline Diet

As the name suggests, this diet removes acid-forming foods like meat, wheat, grains, sugar and dairy and focusses on lots of alkaline-promoting foods like fish, vegetables and fruit. The theory is that excess acid in the body causes weight gain, and so removing these acidic foods will help you lose weight. In general, the advice is really good to encourage general healthy eating; lots of veg, fruit, nuts, seeds and legumes and cutting down on meat, sugar, alcohol, caffeine and grains. Because of the reduction (or complete removal) of things like meat and dairy, it can be good for vegan dieters. Generally, because you're thinking more about the quality of the food you're eating and focussing on lots of fruit and veg, it will naturally lower your calorie intake, which of course will help you to lose weight. And, as we know, it's never a bad thing to limit your intake of sugar and processed foods.

The thing is, your body regulates it's acidity levels (pH balance), whatever your diet. That's one of the things it's naturally able to do; you don't need a diet to do this. It can be tricky to get your head around what you can and can't eat, and meal planning can take longer. Some stricter versions of the diet can cut out food groups entirely, for example dairy, which can lead to a lack of key nutrients (like calcium) unless you're careful.

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This programme involves very low-calorie meal replacement alongside counselling. It's primarily aimed at overweight people, with a BMI of at least 25, and particularly those classed as obese with a BMI of over 30. Similarly to SlimFast, it uses pre-prepared food packs made up of shakes, soups and bars, and no meals made from scratch by the dieter (unless you've not got a huge amount of weight to lose, and then you're able to have one meal from a list of approved ones). This does mean it's really easy to follow and convenient for those with little time. As it's so low-calorie, you'll lose weight quickly and the counselling is a good support system to help you understand your eating habits, your relationship with food and could help you stick to healthy habits once you've come off the plan.

IMO, LighterLife should only be considered by very overweight people who haven't been able to lose weight by other meals. It really is extremely low-calorie, which can cause issues and is very unsustainable in the long-term (and it's recommended that you consult with your GP before embarking on a LighterLife plan). Because you're only allowed the packs of food, it can be boring and difficult in social situations; and if you don't like the taste of the food (or have allergies), you'll really struggle. Side effects such as bad breath, dizziness, insomnia, nausea and constipation are common due to the lack of fibre and 'proper' food. Because it's so low-calorie, it is likely to reduce the dieter's resting metabolic rate (the amount of calories your body burns naturally, just to survive), and so it's likely that you'll put weight back on after finishing the programme as your metabolism will have slowed.

Notice a pattern with these diets? They ALL reduce your calorie intake, whether that's their primary claim or not. At the end of the day, weight loss is all about calories IN versus calories OUT. Basically, you'll only put on weight if you're consuming more calories than you burn, and vice versa.

If you want to change your weight sensibly (and keep that weight off too), you need to change your lifestyle. Diets like I've mentioned above can help give you that kick up the arse you need to start eating more thoughtfully, but generally they're not sustainable and are tricky to stick to in the long run. If you find one that works for you, that you're happy following and that allows plenty of fresh food (namely protein, fruit, vegetables and wholegrain carbohydrates), then perfect.

The key though is to find a nutrition plan that works for YOU; we're all different. Some people prefer low-fat and others thrive on high fat, low carbs.

Choose a balanced, healthy diet that you enjoy following and you'll stick to it, meaning you'll lose weight and keep it off.

Written by Samantha Neades / Personal Trainer / Cheltenham Women's Fitness

Featured Image Credit: Pixabay

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