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The 1:1 Diet Nutritionist Mark Gilbert BASc, RNutr, CISSN

Mark has been involved in nutrition, fitness, and healthcare for over 25 years and is currently a Nutritionist for The 1:1 Diet by Cambridge Weight Plan. Mark helps us ensure each of our products contain the very best in nutrition, ranging from all vitamins, minerals, and more to give our dieters the opportunity to change their health, as well as gain weight-loss.

Mark's Mythbusters

TV Expert

Did you see The 1:1 Diet on  @GBNewsOnline ? Our nutritionist, Mark Gilbert, shared key research about how losing weight can help improve many health problems, for example, diabetes, fertility problems and menopausal symptoms. Then the amazing dieter and Consultant Deborah Adams talked about how she has lost 8st with The 1:1 Diet and transformed her life.

Mark also appeared on Sky News Australia to talk about how people are finding diets from their friends or the internet instead of using an evidence-based approach to maintain a healthy weight. "

"Most people find a diet from a friend or the internet, and they are not using evidence-based, scientifically validated behaviour change” he told Sky News Australia.

Mark appearing on GB News.

Mark appearing on Sky News.

About Mark...

Mark has been involved in nutrition, fitness and healthcare for over 25 years and is currently Nutritionist for The 1:1 Diet by Cambridge Weight Plan and Science Officer for TDMR Europe. He obtained his BASc in Nutrition in 1997 from Ryerson University (Toronto), is a registered nutritionist (RNutr), and is a certified sports nutritionist (CISSN). He also studied exercise physiology at York University (Toronto).

Formerly, Mark was Vice Chair of the European Specialist Sports Nutrition Alliance, Director of Consumers for Health Choice, author, international speaker, on the advisory board and columnist for Muscle & Fitness, Flex and Muscle Insider magazines, founder of MuscleDiet and co-founder of FitnessGenes, Ltd.

Mark has also worked with doctors, dietitians and specialist nurses in the NHS, advising and providing training on the use of enteral and parenteral nutrition and pharmaceuticals and worked with the police and the courts as an expert witness. 

Mark's Diet Mythbusters

Expert Nutritionist Mark Gilbert goes through the top 5 current myths around dieting, The 1:1 Diet plan, and losing weight.

More about Mark's Mythbusters

Rapid weight loss

Hunger issues

Real food diets

A word from Mark...

"I’ve spent a substantial proportion of the last 30 years reading research and working with people (and companies) to improve their health and body composition.  I’ve worked with the world’s top bodybuilders, athletes, sports nutrition companies, and diet brands, and I can honestly say that of all the diet programs I’m aware of, The 1:1 Diet has the most impressive body of research to demonstrate its effectiveness. I simply wouldn’t have joined this company if it didn’t have a large and impressive body of the highest-quality research on its efficacy.

When people go on this diet, they don’t just lose weight, virtually every key measure of health gets better.

Uniquely, The 1:1 Diet also has long-term (multi-year) studies showing excellent maintenance of weight loss – perhaps the most difficult part of the dieting/weight-loss journey!"

The Weight of Nation

The Weight of the Nation 2024. A deep dive into the relationship between weight, mental health, and overall wellbeing.

Welcome to our annual review of research conducted on behalf of The 1:1 Diet by Cambridge Weight Plan. This year, we polled a sample of over 2,000 UK adults to shine a light on the nation’s relationship between weight and wellbeing.

“It’s never been more vital to raise awareness and understanding of the links between weight, diet, and mental and physical health.” - Mark Gilbert, Nutritionist

The Research...

"So why did I say that The 1:1 Diet by Cambridge Weight Plan is the most effective in my intro? Well, in my opinion, that’s where the research points…but don’t take my word for it. Let’s first look at the conclusions of just one of the dozens of independent studies that tested our diet. Here are the scientist’s conclusions from the University of Oxford ‘DROPLET’ study: compared to the ‘usual weight management protocol’,"

The 1:1 Diet ‘leads to substantially greater weight loss and improvements in the risk of cardiometabolic disease. 

Average weight loss was 1½ stone, three and a half times greater than the diet strategy considered best by healthcare providers. When we talk about ‘cardiometabolic disease’ reduction, this means that the diet causes a substantially lower risk of heart attack, stroke, insulin resistance, diabetes, fatty liver disease, and high blood pressure, among other diseases."

The Health Benefits

Mark helps to ensure that each of our fantastic nutritionally complete meals contains 169 health benefits.

More about the 169 Health Benefits

169 Health Benefits

Gut Health


A final note...

"Finally, with The 1:1 Diet, you can be confident that our tasty food products provide quality nutrition and help you stay on track. Each product is formulated to deliver one third of your daily essential nutritional requirements, including being high in quality protein, vitamins, minerals and other essential nutrients.

They also help to minimise hunger and cravings. We know from interviews of subjects in the DiRECT study that our diet is easier than expected to stick to and in the DROPLET study, 62% of study subjects continued using The 1:1 Diet after the study ended, despite now having to pay for it themselves after the study.

In conclusion, if you are looking to lose weight, improve your health, and change your life... it's time to get on The 1:1 Diet plan."


Like what Mark is saying? Time to try the diet... Order a Taster Pack

The 1:1 Diet now offers you the opportunity to buy a Taster Pack before going on plan with a Consultant. Get 6 fantastically nutritious products delivered straight to your door for only £9.99 (€11.49) with free delivery. You'll also get £10 off your first order with a Consultant. 

Order a Taster Pack