Low carb, Paleo or fasting – which diet is best?

January 31, 2018 by Duane Mellor And Paul D Mcardle, The Conversation
Credit: Ekaterina Markelova/Shutterstock

At this time of year, we are bombarded with books and TV shows telling us what we should be eating and how best to lose weight. Particularly in vogue are low-carb diets, Paleo diets and intermittent fasting diets. But which diet is the most effective for sustained weight loss – not to mention good health?

First, let's look at low-carb diets, which include Atkins, Dukan and, more recently, the Pioppi diet. The argument behind these diets is that carbohydrates are bad for us because they are broken down into glucose, which stimulates the release of insulin, and insulin helps the body store the energy from as fat – especially around our middles.

What is missed in this argument is that it is not only carbohydrates that encourage us to make insulin. Foods high in protein and fat do this, too. Beef, for example, increases insulin to a similar level as breakfast cereals.

Related to low-carb diets are the evolutionary-type approaches, such as the caveman diet and the Paleo diet. These diets recommend shunning processed foods and following a diet similar to that of our ancestors in the Paleolithic period – a period that began about 2.6m years ago and ended about 12,000 years ago.

Definitions of this diet vary, but they tend to exclude grains, which often results in a low-carbohydrate diet. Dairy products are also avoided. Both low-carb and Paleo diets encourage eating plenty of fresh food, including vegetables, and little or no highly processed food.

Evidence suggests that low-carb diets can help you lose weight, reduce your risk of type 2 diabetes and, perhaps, your risk of heart disease. However, these three potential benefits are largely linked to the energy restriction they cause and are not directly related to avoiding carbohydrates.

The reason for the drop in energy (calorie) intake is that carbohydrates normally make up a large part of the Western diet. Banishing carbs makes it difficult to make up for the lost energy intake because the food industry is geared to providing plenty of carbohydrate-rich foods.

Other studies suggest that eating protein and fat keep you feeling full for longer, and may suppress appetite that way. However, more research is needed to prove this theory.

There is some evidence that a can help you lose weight, for up to six months. And a study of people with type 2 diabetes suggests that it can help reduce the need for diabetes medication, even after two years.

The news is not all positive, though. Paleo diets, in particular, can cause side effects, such a diarrhoea, headaches and weakness. And both Paleo and low-carb diets tend to be more expensive than a regular healthy diet (as per government guidelines), and require careful planning to meet nutritional needs.

The Eatwell guide. Credit: Food Standards Agency

Fasting

Intermittent fasting diets, such as the 5:2 diet and the warrior diet, are another recent fad. They usually involve going for 14 to 36 hours with few or no calories.

The 5:2 diet involves eating a normal amount of calories for five days of the week and eating reduced calories (25% of normal calorie intake) on two non-consecutive days. The warrior diet involves eating just one large meal a day.

These types of diets have been shown to result in . In a study published in the International Journal of Obesity, the 5:2 diet not only resulted in a loss of over 6kg, on average, in overweight and obese women, over a six-month period, it also improved several important markers of health, including LDL cholesterol, triglycerides and blood pressure.

The important thing for people embarking on fasting diets to remember is: you need to meet all of your nutritional needs, as per the UK government's Eatwell guide.

The diets we've discussed almost all recommend eating more vegetables and less sugar, refined carbohydrates and highly processed foods. The advocates of these diets differ on the role of fats and carbohydrates, but they all encourage people to think more about food and take control of the food they eat.

Reclaiming the word 'diet'

The evidence seems clear, most diets are equally effective when it comes to weight loss. The important thing is to find a diet that works for you – one you can enjoy in the long term.

Perhaps we need to remember the origins of the word diet, coming from the Greek "diata", meaning way of life. This meaning has been adapted over time to mean a restriction. It's time we reclaim the word for its true meaning, and look to find ways of eating that are both enjoyable and improve health.

What we have learned from countries where people live long and healthy lives is that they tend not to focus on specific diets – counting calories, fussing about carbs – instead they eat local produce that is affordable and enjoyable.

Explore further: Low-fat diet, low-carb diet—or 'low both'?

Related Stories

Low-fat diet, low-carb diet—or 'low both'?

November 9, 2017
(HealthDay)—Low-carb diets are often thought of as fad diets that might yield a rapid initial weight loss, but aren't sustainable or necessarily healthy. But when there's academic research behind the approach, it's worth ...

The Keto diet—is eating more fat the key to weight loss?

August 10, 2017
Models, athletes and celebrities swear by the ketogenic "keto" diet to help shed those unwanted pounds. The keto diet encourages eating more cheese, butter and bacon; it's a low-carb, high-fat diet akin to the Atkins Diet ...

Medical myth: Cutting carbs is the best way to lose weight

August 27, 2012
There seems to be an endless number of fad diets and "golden rules" for weight loss. One of the most popular of these rules is that cutting carbohydrates (carbs) is the best way to lose weight.

What's your best diet for 2018? Experts rate them

January 3, 2018
(HealthDay)—Your New Year's resolution diet should be based on a well-balanced eating plan that fits your lifestyle, rather than a weird fad replete with food restrictions.

Do ketogenic diets help you lose weight?

September 20, 2017
Is a ketogenic diet effective for weight loss? The answer depends on whether it achieves a reduction in total kilojoule intake or not.

Low-carb diets safe in short term, more effective for weight loss than low-fat diets, study says

December 13, 2016
People deciding between low-carb and low-fat diets should know the research shows a slight advantage for low-carb diets when it comes to weight loss, according to an article published today in The Journal of the American ...

Recommended for you

Widespread declines in life expectancy across high income countries coincide with rising young adult, midlife mortality

August 15, 2018
The ongoing opioid epidemic in the United States is a key contributor to the most recent declines in life expectancy, suggests a study published by The BMJ today.

Diets high in vegetables and fish may lower risk of multiple sclerosis

August 15, 2018
People who consume a diet high in vegetables and fish may have a reduced risk of multiple sclerosis, new research led by Curtin University has found.

Can sleeping too much lead to an early death?

August 15, 2018
A recent study in the Journal of the American Heart Association has led to headlines that will make you rethink your Saturday morning sleep in.

Parental life span predicts daughters living to 90 without chronic disease or disability

August 15, 2018
Researchers at the University of California San Diego School of Medicine report that women whose mothers lived to at least age 90 were more likely to also live to 90, free of serious diseases and disabilities.

Mixing energy drinks with alcohol could enhance the negative effects of binge drinking

August 14, 2018
A key ingredient of energy drinks could be exacerbating some of the negative effects of binge drinking according to a new study.

New study finds fake, low-quality medicines prevalent in the developing world

August 10, 2018
A new study from the University of North Carolina at Chapel Hill found that substandard and falsified medicines, including medicines to treat malaria, are a serious problem in much of the world. In low- and middle-income ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.