Why 4:3 Intermittent Fasting Beats Daily Dieting | Image Source: www.verywellhealth.com
DENVER, Colorado, April 14, 2025 – A one-year study found that 4: 3 intermittent fasting, where individuals fast for three non-consecutive days a week and eat without restrictions to the other four, resulted in weight loss more than the traditional daily restriction of calories. Published in the Annals of Internal Medicine, this research offers new ideas about two of the most popular diet strategies – intermittent fasting and daily calorie counting – and provides convincing evidence that less can actually be more when it comes to the frequency of food consumption.
Researchers at the University of Colorado’s Anschutz Medical Campus and the University of Tennessee, Knoxville, led by Dr. Victoria Catenacci and Dr. Danielle Ostendorf, compared the effectiveness of these two methods of weight loss over a 12-month period. The results were not statistically significant, they were surprisingly human. According to the study, participants in the intermittent fasting group lost an average of 6.4 pounds more than those who joined the traditional calorie restriction. But perhaps more worthy is the apparent psychological and behavioral edge that model 4: 3 fast seemed to offer.
The results question the wisdom of conventional diet, especially for those who have long seen calories count as the golden norm. But before making radical changes to their eating habits, experts warn that the context, sustainability and individual health factors count as much as calories burned or pounds spilled.
What is 4: 3 Ayuno Intermittent and how does it work?
Model 4: 3 Intermittent Fasting (IF) involves fasting three non-consecutive days each week, with a significantly reduced calorie consumption to 400-600 calories for women and 500-700 calories for men in those days. In the remaining four days, individuals are not required to count calories, but are encouraged to make conscious decisions about food. This contrasts with the daily calorie restriction (DCR), which is to reduce calorie intake daily to reach a weekly deficit of about 34%.
According to Catenacci and Ostendorf, the strategy is designed to achieve a balance, difficult but unbearable. It’s not a daily correction, but it’s not a free pass either. The structure seems to relieve cognitive and emotional fatigue that often accompanies constant monitoring of calories, creating a model easier for some to adhere to over time.
Q: Why do people prefer 4: 3 intermittent fasting to the daily restriction of calories?A: Less days of restriction means fewer days of hunger, fatigue in decision and net number. This model can also be more lenient for social canteens and weekend indulgences.
The results of the surprise weight loss explained
After 12 months, the fasting group lost an average of 7.6% of its body weight, compared to 5% in the calorie group. This is about 6.4 pounds more, which may seem modest, but more than a year, may be the difference between reversing prediabetes or not, or lowering blood pressure enough to lower the medication.
Like Krista Varady, PhD, nutrition expert at the University of Illinois, Chicago, said this study is unique. “This is the only study to date in humans that has shown that intermittent fasting is more effective than reducing calories,” he said. Unlike previous meta-analyses, including a systematic review of 2024, this research took a more controlled and personalized approach, with participants receiving behavioural support and dietary advice.
Q: Did the group on intermittent fasting eat fewer calories in general?A: Yes. Although you are allowed to eat freely on non-fast days, the fasting group always consumes fewer calories on average during the week.
Behavioral simplicity: A factor hidden in the success of the diet?
Counting each bite can feel like a second job. Although both groups reported the same weekly energy deficit (34% of the base), the fasting group was not responsible for daily monitoring. This is a game change for compliance. Calorie tracking, although effective, can cause burns, recording errors or simple mental fatigue. This can cause a slip over time.
Allison Rhodes, M.D., a specialist in obesity medicine at the Wexner Medical Center at Ohio State University, echoed this sentiment, noting that ”total adherence to the calorie count requires a cognitive burden that not everyone can bear in the long term.” Model 4: 3 allowed participants to focus the effort a few days a week instead of each day.
Q: Could this facilitate intermittent fasting over time?A: Potentially, yes. Reducing the frequency of restrictions and psychological relief in days of non-fasting can improve long-term compliance.
What about the science behind fasting?
There may also be biological benefits related to fasting, not just behavioral. According to Dr. Michael Snyder, medical director of the Rose Medical Center and obesity expert in FutureHealth, fasting can influence hormones such as leptin and ghrelin, which regulate hunger and satiety. In addition, an increase in insulin sensitivity during fasting periods could encourage fat burning on fat storage.
Although these hormonal effects are still being studied, they provide scientific plausibility for the reason that fasting may exceed the traditional diet, especially in cases of insulin resistance or metabolic syndrome. However, the study noted that the observed weight loss was probably due to a higher calorie deficit rather than a “metabolic cache”
Q: Does intermittent fasting alter metabolism?A: Insulin sensitivity and hunger regulation can be improved, but more research is needed to understand its metabolic effects.
Is Method 4: 3 safe for all?
No scheme is unique. The study excluded children, adolescents, the elderly, pregnant or nursing women and people with chronic diseases such as diabetes or heart disease. Therefore, although model 4:3 was considered effective for the 18-60 years interval with BMI between 27 and 46, it may not be appropriate, if not safe, for all.
Dr. Snyder warned that prolonged fasting can increase cortisol levels and may alter hormonal balance in some people, especially women. People with a history of eating disorders, thyroid disorders or hypoglycaemia should approach intermittent fasting carefully and preferably with professional supervision.
Q: Who should avoid intermittent fasting?A: People with diabetes, hormonal disorders, eating disorders, pregnancy or breastfeeding should first consult a health care professional.
Make it work: Practical tips to try 4: 3 Ayuno intermittent
If you consider approach 4: 3, start slowly. Ostendorf recommends starting with one day of fasting a week and gradually building. In fasting days, many participants found it easier to eat their limited calories in a living room rather than spread them. Hydration is also crucial: non-calorie drinks such as sparkling water, black coffee or herbal tea can help manage hunger.
The study participants received weekly support from a registered dietitian. Although not everyone has access to this level of guidance, mobile apps and online communities can provide some responsibility and education. However, nothing replaces the individualized care of a professional.
Q: How can we start plan 4: 3?A: Start with a quick day a week, focus on hydration and monitor your body’s response. Ask for professional advice when possible.
What about long-term success and sustainability?
The study followed participants for 12 months, which is commendable in diet research, but the long-term results are still unknown. Is the weight going to stay? Will health markers improve further? These are questions for future studies. In addition, the behavioral support offered in this trial may not reflect the conditions of the real world, where most people stay for a single diet.
However, the implications are promising. By combining simplicity, flexibility and periodic intensity, 4: 3 intermittent fasting seems to offer physiological and psychological benefits. It may not work for everyone, but it is an approach that respects the rhythms of real life, a key ingredient in the long-term success of health.
Q: Is this the end of daily calorie counting?A: Not at all. The daily number of calories remains effective for many. But 4: 3 intermittent fasting offers a convincing alternative, especially for those struggling with the daily routine of food.
As the doctor said. Keerthana Kesavarapu from Rutgers Health, membership is the key: “The study theories that daily caloric restriction is more difficult to maintain than diet 4: 3. For people who are trying to lose weight in a long-lasting, mentally manageable way, this method can hit this soft place.
