New research has suggested intermittent fasting could be more effective than a calorie controlled diet for weight loss.
The eating method has become extremely popular in recent years as a way to lose weight, and is favoured by a number of celebrities, including Hugh Jackman, Cameron Diaz, Jennifer Aniston, Kourtney Kardashian, former prime minister Rishi Sunak, and more.
Unlike traditional diets, which focus on what you eat, intermittent fasting focuses on when you eat, cycling between periods of eating and fasting.
A new study, by researchers from the University of Colorado School of Medicine and published in the journal Annals of Internal Medicine, has found people on the popular 4:3 intermittent fasting plan showed “modestly greater” weight loss over 12 months than those on a daily caloric restriction diet.
The 4:3 plans involves restricting calorie intake for three days a week, then eating as you like for the other four days.
The clinical trial compared the effects of 4:3 intermittent fasting to daily caloric restriction on weight loss when combined with comprehensive behavioural support in adults who were overweight or obese.
The study randomly assigned 165 overweight adults to either 4:3 intermittent fasting or calorie restriction for 12 months to compare weight loss.
Results showed 58% of those in the fasting group achieved weight loss of at least 5% at 12 months compared to 47% in the calorie restriction group.
Commenting on the findings study first author Professor Victoria Catenacci said: “At 12 months, participants in the 4:3 intermittent fasting group had a minus 7.6% change in body weight compared to minus 5% in the calorie restriction group.”
The research team said their findings suggest that because fasting does not require participants to focus on counting calories and restricting food intake every single day, it may result in “greater adherence” and should be considered within the range of evidence-based dietary weight loss approaches.
Further research has also suggested that intermittent fasting can help reduce body fat and promote weight loss. When you fast, the body goes into a state of ketosis (fat burning), leading to more efficient fat metabolism.
One study published in Obesity Reviews in 2021 concluded that intermittent fasting can be as effective as traditional calorie restriction for weight loss. Research also shows that IF helps to reduce visceral fat, which is linked to higher risks of metabolic diseases.
But while some experts – like the late Dr Michael Mosley – swear by the benefits of intermittent fasting, others remain cautious about its long-term effects. Recent studies provide valuable insight into the potential pros and cons of this eating pattern.
What are the pros of intermittent fasting?
Improved insulin sensitivity
It has been suggested that Intermittent fasting can improve insulin sensitivity, which helps the body regulate blood sugar levels more effectively.
This is particularly important for people at risk of developing Type 2 diabetes. A 2020 study in Cell Metabolism demonstrated that fasting for 16 hours a day helped participants lower their blood sugar levels and improve insulin sensitivity without the need for medication.
Brain health and cognitive function
Research on intermittent fasting’s effects on the brain has shown promising results. The fasting period triggers the production of brain-derived neurotrophic factor (BDNF), a protein that supports the survival and growth of neurons.
A 2021 study in Nature Reviews Neuroscience found that intermittent fasting improved cognitive function, neuroplasticity, and could even reduce the risk of neurodegenerative diseases like Alzheimer’s.
Increased longevity and anti-aging benefits
A growing body of research suggests that intermittent fasting may increase lifespan by reducing oxidative stress and promoting cellular repair processes. Studies in animals have shown that fasting can extend life expectancy, and human studies are beginning to show promising results as well.
A 2022 study published in Science Translational Medicine indicated that intermittent fasting increased markers of longevity and reduced markers of aging, such as inflammation and oxidative stress.
Simple to follow
One of the biggest advantages of intermittent fasting is its simplicity. Unlike traditional diets that require constant meal planning, calorie counting, or eliminating food groups, IF simply requires time-restricted eating. Many people find this more sustainable over the long term because it doesn’t require drastic changes to food choices.
What are the cons of intermittent fasting?
While intermittent fasting offers several benefits, it’s not without its drawbacks. Here are some of the common downsides reported in studies and personal experiences:
Potential for overeating during eating windows
One of the key risks of intermittent fasting is the temptation to overeat during the eating windows. Some individuals may find themselves consuming more calories than they would if they were eating regularly throughout the day, which could negate the benefits of fasting.
In 2021, scientists found that some participants gained weight or failed to lose weight while practicing intermittent fasting due to excessive caloric intake during eating windows.
Possible negative effects on women’s hormonal balance
For some women, intermittent fasting can disrupt hormonal balance, particularly during menstruation or in women with polycystic ovary syndrome (PCOS). A 2022 study found that prolonged intermittent fasting may interfere with menstrual cycles and lead to an imbalance in reproductive hormones, which could affect fertility.
Risk of nutrient deficiencies
Because intermittent fasting restricts the time available for eating, there’s a risk of not getting enough nutrients, especially if meals are not well-balanced. A 2021 study in Nutrients found that people practicing IF without proper meal planning were at an increased risk of deficiencies in important vitamins and minerals, such as calcium, vitamin D, and magnesium.
Watch: How to start intermittent fasting safely
Possible increased stress and anxiety
Some people report feeling stressed or anxious about fasting, particularly during the early stages when the body is adjusting to longer periods without food. In a study published in Psychology & Health, researchers found that participants practicing intermittent fasting experienced increased anxiety and irritability, especially when fasting for extended periods.
Not suitable for everyone
Intermittent fasting may not be suitable for people with certain medical conditions, including eating disorders, low blood pressure, or those who are pregnant or breastfeeding. In fact, experts recommend that individuals with a history of eating disorders should avoid restrictive eating patterns altogether. It’s always important to consult a healthcare provider before beginning any fasting regimen.
Should I try intermittent fasting?
Intermittent fasting can offer impressive health benefits, from weight loss to improved metabolic health and potential longevity. However, it is not a one-size-fits-all approach. While some people thrive on it, others may face challenges such as nutrient deficiencies, hormonal imbalances, or increased stress.
Ultimately, whether intermittent fasting is right for you depends on your health goals, lifestyle, and how your body responds to the fasting regimen. As with any lifestyle change, moderation and balance are key.
Before embarking on any change in your diet, you should consult your GP and discuss what options may be best for you.
Additional reporting SWNS.
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