Diet A-Z

Weight Loss

Diet A-Z

Not sure where to start with dieting? Our A-Z of diet plans tells you everything you need to know when choosing which plan is best to help you eat healthily.

Not sure where to start with dieting? Our A-Z of diet plans tells you everything you need to know when choosing which plan is best to help you eat healthily.

With the sheer amount of plans out there plugging ‘guaranteed’ approaches to losing weight, it’s easy to get tied up by all the conflicting information. As with any health and fitness considerations, you need your wits about you to weigh up the pros and cons and get past the contrary reviews and rankings. There are no definitive answers. It’s just about finding the best fit for you. 

Try comparing the plans on various criteria, such as the ability to produce short and long-term weight loss, nutritional value, safety impact, and the potential to reduce the risk of serious health issues. Whatever plan you prefer, note that no diet offers a viable quick fix, and those polling most positively require hard work if your goal is to lose weight healthily. It’s also often down to whether you have the time, effort or motivation to properly stick to each plan.

Whatever plan you prefer, note that no diet offers a viable quick fix...

Here is an overview of a few of the best known or best received diets to choose from:  

The Abs Diet

The claim: drop up to 12 lb (approx. 5kg) of stomach fat in two weeks and maybe even get a six-pack in six weeks.  

The theory: built around 12 nutrient-packed foods thought to provide all the vitamins, minerals and fibre you need, while triggering lean muscle growth and helping burn fat. Eating six times a day, as required, keeps energy levels high and hunger at bay. Its creator argues against calorie-counting, feeling overly-restrictive diets often lead to a craving to binge and fall off the wagon. Menu plans emphasise protein with every meal and snack, filling you up for longer than carbs and spurring lean muscle growth and fat burn.  

Atkins Diet 

The claim: lose 5 lb (approx 2kg)  in your first week, then 1-2 lbs (approx. 0.5-1kg) a week from there.  

The theory: the body is an engine, with carbs providing the fuel. Limiting carbs makes the body turn to an alternative fuel - stored fat. Sugars and simple starches like potatoes, white bread, and rice are all but squeezed out in favour of fat like chicken, meat, and eggs. With that fat burned, the weight comes off. That said, the Atkins diet has been criticised as a fad by dieticians, who believes it’s nutritionally poor, and can cause side-effects.    

Biggest Loser Diet 

The claim: six weeks of healthy food and regular exercise leads to weight loss and helps prevent or reverse diabetes, cuts the risk for cancer and dementia, guards against heart disease, and boosts your immune system.  

The theory: cut calories, work out and watch the pounds melt off. Their answer is to eat regular meals, your calorie intake coming from fruit, veg, lean protein sources, and whole grains, keeping an eye on portion control and getting off the sofa.

The Cambridge Diet   

The claim: a choice of flexible meal-replacement products trigger rapid weight loss.  

The theory: the plan’s bars, soups, porridges and shakes become your sole source of nutrition or are used alongside low-calorie regular meals. Along the way, you receive advice and support on healthy eating and exercise. Meals are nutritionally balanced, so you're likely to get the vitamins and minerals you need. There can be side-effects though from cutting back on carbs and fibre. The hard part is sticking to the plan, and while rapid weight loss can be motivating, it is unsustainable.  

DASH (Dietary Approaches to Stop Hypertension) Diet

The claim: by keeping blood pressure low, you reduce the risk of heart disease and strokes, and decrease ‘bad’ cholesterol and triglycerides in the blood, also linked to cardiovascular problems.   

The theory: a relatively simple plan developed as a way to lower blood pressure. It tells you how many calories you should eat for your age and activity level, and suggested you should have lots of fruit and vegetables and cut back on salt. Scored a best-in-market rating in a recent US survey.  

Dukan Diet   

The claim: lose up to 10 lb (approx. 4.5kg) within the first week, and then continue at a drop 2-4 lb (approx. 1-2kg) a week until you reach your goal, eating as much as you like of the approved foods. If you follow the rules, you’ll never regain.  

The theory: counting calories isn’t the key to weight loss. Protein is. It’s filling, takes time and work to digest, and has very few calories per gram compared to carb-heavy foods. Carbs are all but squeezed out, leading to fast weight loss. There may be side-effects though, and while rapid weight loss can motivate, it can be unsustainable and unhealthy.  

Mayo Clinic Diet   

The claim: shed 6-10 lb (approx. 3-4.5kg)  in two weeks and continue losing 1-2 lbs (approx. 0.5-1kg) weekly until you’ve hit your goal weight.  

The theory: rethink your eating habits, break bad eating habits and replace them with good ones with the help of a special food pyramid. This lesser-known spin on dieting claimed a bronze medal in a recent survey, and inspires its users to opt for healthier alternatives, not least suggesting fruit and veg for those inevitable snacking moments. The emphasis is on foods with low energy density like whole grains, so you can eat more but take in fewer calories as you do.  

The Paleo Diet   

The claim: weight loss and maintenance, and prevention or control of Type 2 diabetes and heart disease.  

The theory: highly-processed, carb-obsessed eating is responsible for our biggest ills, so why not go back to the Paleolithic period when our diet wasn’t full of junk food and pasta? Eat as we did when we were hunting and gathering: animal protein and plants. If a caveman didn’t eat it, nor should you. That way, you cut out refined sugar, dairy or grains and instead focus on lots of meat, fish and fruit. That said, there are no accurate records of the caveman diet, this diet runs counter to current health advice on meat consumption, and it’s no good for vegetarians.  


The claim: drop 1-2 lbs (approx. 0.5-1kg) weekly.  

The theory: restrict calories and portion sizes through specific shakes, meal and snack bars, replacing your breakfast, lunch and snacks, so you get the right amount of the right nutrients. You also prepare a 500-calorie meal each day, so there’s room to enjoy small portions of favourite foods. You stay on the diet as long as you want. Once you reach your goal, you’re advised to have one shake a day, up to two low-fat snacks and two healthy meals. However, meal replacement diets do little to educate people about eating habits and change their behaviour. There’s a risk of putting the weight back on again once you stop.  

The Slimming World Diet

The idea: lose about 1-2 lbs (approx. 0.5-1kg) a week, swapping high-fat foods for low-fat foods that are naturally filling.  

The theory: you choose your food from a list of low-fat foods such as fruit, veg, pasta, potatoes, rice, lean meat, fish and eggs, which you can eat in unlimited amounts. There’s no calorie counting, no foods are banned, and you’re allowed occasional treats. You get support from fellow slimmers at weekly group meetings, and an exercise plan to become gradually more active.  However, without learning about calories and portion sizes, you may struggle to keep the weight off in the long term.

TLC (Therapeutic Lifestyle Changes) Diet

The claim: lower your ‘bad’ cholesterol (LDL) by eight to 10% in six weeks, reducing the risk of cardiovascular disease by cutting back sharply on fat, particularly saturated fat.  

The theory: saturated fat (fatty meat, whole-milk dairy and fried foods etc.) bumps up bad cholesterol, which increases the risk of heart attack and stroke. Cutting back on saturated fat, along with strictly limiting daily dietary cholesterol intake and getting more fibre, can help people manage high cholesterol, often without medication. Finishing second in that survey, the TLC Diet is a heart-healthy alternative. However, it’s not that easy to stick to, and you need to read nutritional labels carefully.  

The Weight Watchers Diet

The claim: drop up to 2 lbs (approx. 1kg) weekly.  

The theory: there’s more to dieting than counting calories. If you make healthy choices that fill you up, you’ll eat less. Every food gets a points value, based on its protein, carbohydrate, fat and fibre. Choices that fill you up the longest ‘costs’ the least number of points, and nutritionally dense foods cost less than empty calories. There’s no limit on the amount of fruit and most veg you eat. The weekly meetings and confidential weigh-ins provide support and extra motivation to encourage long-term behaviour change. However, when you begin, working out the points system can be just as time-consuming as simply counting calories, and some people feel pressured into buying branded plan foods.  

The 5:2 Diet

The claim: lose weight, improve your lifespan and brain function, protecting against conditions such as dementia.  

The theory: based on intermittent fasting, you eat normally for five days a week and fast on the other two - with restricted calorie intake. Devised in the UK and popular around 2012, critics suggest evidence of its effectiveness is limited. One study suggested this plan may help to lower the risk of certain obesity-related cancers, such as breast cancer. But if you are considering it, talk to your doctor first, and note that on non-restricted days, you still need to make healthy choices and be active.