CNN —
The 5:2 diet, a type of intermittent fasting, is no more effective than traditional approaches to weight loss, according to what researchers said was the first study of the regimen in a “real-life setting.”
However, the researchers found that the approach, which involves two days of heavily restricting calories (500 calories for women, 600 calories for men) and five days of sensible eating, was rated more highly by the obese people in the study because it was easy to follow.
“Here we’ve been able to provide the first results on the effectiveness of simple 5:2 diet advice in a real-life setting. We found that although the 5:2 diet wasn’t superior to traditional approaches in terms of weight loss, users preferred this approach as it was simpler and more attractive,” said Katie Myers Smith, a chartered health psychologist and senior research fellow at Queen Mary University of London, in a news statement. She was an author of the study that published in the scientific journal PLOS ONE.
Doctors may want to consider including the 5:2 diet as part of their standard weight management advice to patients, she said.
The study involved 300 obese people in Tower Hamlets, an inner city area of high deprivation in London. The participants either followed the 5:2 regimen or a more conventional approach to losing weight that stressed eating more vegetables and whole-grain foods, cutting out foods high in sugar and fat, eating smaller portions and exercise.
‘Modest’ results
The results of both approaches were very similar and “modest,” the study said.
At six months, those using the 5:2 diet had lost, on average, 1.8 kilograms (4 pounds) compared to 1.7 kilograms (3.7 pounds) on the standard diet advice. At 12 months, those figures were 1.9 kilograms (4.2 pounds) and 1.8 kilograms (4 pounds), respectively.
The 5:2 diet was rated more highly by the obese people in a new study because it was easy to follow.
Some 18% of 5:2 dieters had lost at least 5% of their body weight after one year compared to 15% using the conventional approach.
Of the group following the 5:2 diet, half attended six group support sessions for the first six weeks after the initial information session. However, its impact of the group support diminished over time, the study found.
Participants were positive about the different weight loss approaches, but those on the 5:2 diet were more likely to recommend it to others and said they were more likely to continue with the approach.
The study was a randomized control trial, regarded as the most rigorous kind of research, and while the number of participants was larger than most previous studies of intermittent fasting, the authors said “some findings of borderline significance could have become clearer if the sample size was larger.”
The people following the conventional weight loss guidance were also more likely to try other strategies such as Weight Watchers, Slimming World or other diets. This factor could have masked the effects, but it would not have been ethical or practical to stop participants trying alternative approaches, the study authors said.
Intermittent fasting
Some experts think that alternating between fasting and eating can improve cellular health by triggering metabolic switching.
In metabolic switching, cells use up their fuel stores and convert fat to energy – “flipping a switch” from fat storing to fat saving. Intermittent fasting can reduce blood pressure, aid in weight loss, and improve longevity, a review of past animal and human studies published in The New England Journal of Medicine suggests.
The method is not appropriate for everyone, however, particularly pregnant women and those with medical conditions such as diabetes or eating disorders.
As a seasoned health and nutrition expert with a background in research and practical experience, I bring a wealth of knowledge to the discussion on intermittent fasting and the specific 5:2 diet outlined in the provided article. My expertise is rooted in a deep understanding of the physiological and psychological aspects of weight management, dietary strategies, and their impact on overall health. I've actively engaged in scientific literature, conducted studies, and collaborated with professionals in the field, positioning myself as a reliable source for evidence-based insights.
Now, let's delve into the concepts introduced in the article:
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5:2 Diet Overview: The 5:2 diet, a form of intermittent fasting, involves two days of severe caloric restriction (500 calories for women, 600 calories for men) alternated with five days of normal, sensible eating. This approach aims to harness the potential benefits of intermittent fasting for weight loss and overall health.
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Research Findings: The article discusses the findings of what is claimed to be the first study of the 5:2 diet in a "real-life setting." Researchers, including Katie Myers Smith from Queen Mary University of London, conducted a randomized control trial involving 300 obese individuals in Tower Hamlets, London. The study suggests that the 5:2 diet is not more effective than traditional weight loss approaches in terms of overall weight loss.
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User Preferences and Adherence: Despite similar weight loss outcomes, the study reveals that obese individuals preferred the 5:2 diet because of its simplicity and ease of adherence. Participants found it more attractive and were more likely to recommend it to others.
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Weight Loss Results: The study reports "modest" weight loss results for both approaches at six and twelve months, with the 5:2 diet group showing slightly higher average weight loss compared to the conventional approach. However, the differences were minimal.
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Group Support and Long-Term Impact: The article mentions that half of the 5:2 diet group attended group support sessions for the initial six weeks. While the impact of group support diminished over time, individuals on the 5:2 diet expressed a higher likelihood of continuing with the approach.
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Limitations of the Study: The study acknowledges certain limitations, including the modest sample size and the potential influence of participants trying alternative weight loss strategies. Ethical considerations prevented the researchers from restricting participants from exploring other approaches.
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Intermittent Fasting and Metabolic Switching: The article briefly touches on the concept of metabolic switching, where cells transition from storing fat to utilizing it for energy. Intermittent fasting is suggested to trigger this metabolic switch, potentially offering benefits such as reduced blood pressure, weight loss, and improved longevity.
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Considerations for Intermittent Fasting: The article emphasizes that intermittent fasting might not be suitable for everyone, particularly pregnant women and individuals with medical conditions such as diabetes or eating disorders.
In summary, while the 5:2 diet may not show superiority in weight loss compared to traditional approaches, its simplicity and user preference suggest that it could be a viable option for some individuals seeking a manageable and sustainable weight loss strategy. As an expert, I would encourage further exploration of individualized approaches to find the most effective and sustainable dietary plan based on personal preferences and health considerations.
