NEJM Which weight loss strategy works better?

"Five people, there must be two fat people" is the current situation of the world's population
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The obesity pandemic, which swept the world nearly two decades before the Covid-19 pandemic, seems to be spiraling out of control
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Since obesity is the main culprit in a series of major chronic diseases such as cardiovascular disease, diabetes, hypertension, asthma, and sleep disorders, losing weight has also become the life goal of most people with lofty ideals
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It is well known that obesity is an energy imbalance caused by chronic caloric intake exceeding energy expenditure
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Today's high-calorie diet combined with a sedentary life>
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what to do? It's the most effective, safest and cheapest way to lose weight by "shutting your mouth" (restricting calories) and "stretching your legs" (exercising your body)
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A calorie-restricted dietary pattern is the oldest known intervention for weight loss and life extension
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In this day and age of overnutrition, this strategy couldn't be more appropriate
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Extensive research and clinical trials confirm that caloric restriction not only reduces body weight, but also reduces age-related disease burden and decline in physiological function
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In addition, the intermittent fasting strategy that has become popular in recent years has also become more and more popular in the weight loss community
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Intermittent fasting strategies are generally divided into three types: one is daily time-restricted eating (novice mode), which narrows the time period for eating to 6 to 10 hours a day and fasts the rest of the time; the other is "5:2" "Fasting (advanced mode), that is, eat normally 5 days a week, and eat very little for the remaining 2 days; another is fasting every other day (hard mode), that is, eat one day, be hungry for one day, eat another day, and be hungry again a day (drinking water or meal replacement during the day)
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Intermittent fasting strategies have also been extensively studied to reduce weight and improve various health indicators
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Looking at it this way, the advantages of calorie restriction and intermittent fasting are similar
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So, which one is better for weight loss? Previously, a small randomized controlled clinical trial based on 36 British obese patients, published in Science Translational Medicine, was the first to directly compare alternate-day fasting (a difficult mode of intermittent fasting) with a calorie-restricted diet strategy for weight loss and calorie restriction.
other influences
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The results of the less than one month trial showed that both dietary strategies resulted in weight loss, but the weight loss in those participants who were hungry for more than ten days with alternate-day fasting was nothing special compared to calorie restriction
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Obviously, the study was conducted on foreigners, with a small sample size and a short duration
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Therefore, it is uncertain whether these two weight loss strategies will allow the participants to maintain the "fruit of victory" in the long-term
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On April 21, 2022, in a new study published in the top medical journal "New England Journal of Medicine (NEJM)" (IF=91.
245), a research team led by Professor Zhang Huijie from Nanfang Hospital of Southern Medical University carried out in Guangzhou.
A randomized clinical trial evaluating daily time-restricted eating (a primary model of intermittent fasting) versus a calorie-restricted diet alone for weight loss and effects on metabolic risk factors in obese participants
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In the new study, researchers recruited 139 obese participants in Guangzhou, with an average age of 31.
9 years and an average weight of 88.
2 kg (BMI: 28 to 45)
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Participants were randomly assigned to a time-restricted diet plus calorie restriction group (69) or calorie restriction alone (70)
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All participants reduced their daily caloric intake by about 25% over the 12-month trial
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Male participants ate a diet of 1500-1800 kcal per day and women 1200-1500 kcal per day
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40-55% of calories in both groups came from carbohydrates, 15-20% from protein, and 20-30% from fat
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The time-restricted diet + calorie restriction group consumed the prescribed calories within 8 hours a day (from 8:00 am to 4:00 pm), and only non-caloric beverages were allowed in the rest of the time; the calorie-restricted group alone had no time-limited daily calorie intake
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Physical activity levels were similar in both groups
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For the first 6 months of the trial, the researchers gave participants a daily protein shake from Zhejiang to help them improve adherence to the reduced-calorie diet
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After 12 months, let's take a look at their weight loss record: Both groups lost weight: the time-restricted diet + calorie restriction group lost an average of 8kg; the calorie restriction group lost an average of 6.
3kg
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Both groups lost body fat: the time-restricted diet plus calorie restriction group lost an average of 5.
9 kg; the calorie restriction group lost an average of 4.
5 kg
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BMI (-2.
9 vs -2.
3), waist circumference (-8.
8 vs -7.
0cm), body fat percentage (-4.
3% vs -3.
0%), abdominal visceral fat area (-26 vs -21.
1cm2), abdominal subcutaneous Obesity-related indicators such as fat area (-52.
2 vs -37) were significantly reduced
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While it appeared that the time-restricted diet + calorie restriction group lost weight better, the researchers said the difference between the two groups was not significant, with similar measures of trunk fat and lean body mass in the extremities
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Let's take another look at how their cardiovascular risk factors changed
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During the 12-month dietary intervention, both systolic and diastolic blood pressures decreased in both groups, with no substantial difference
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In addition, fasting blood glucose levels, 2-hour postprandial blood glucose levels, insulin resistance index, and blood lipid levels were also reduced in the two groups, with no significant difference
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In terms of compliance, after 1 year, 84.
0% of the participants in the time-restricted diet + calorie restriction group persisted to the end; 83.
8% of the participants in the calorie-restricted group completed the prescribed tasks
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In addition, during the 12-month dietary intervention, participants in both groups experienced no serious adverse events and similar rates of mild adverse events, such as fatigue, dizziness, headache, decreased appetite, epigastric pain, dyspepsia, and constipation
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This suggests that both dietary strategies are safe
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In conclusion, after a one-year dietary intervention, either a time-restricted diet plus a calorie restriction strategy or a calorie restriction strategy alone, both regimens achieved similar success in obese patients in China
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The findings are the same as those of the small UK trial of obese people, that time-restricted eating does not appear to have much of an advantage
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This new study re-emphasizes the importance of keeping your mouth shut for weight management and health
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Paper link: https:// https://stm.
sciencemag.
org/content/13/598/eabd8034 Related reading: Science is heavy! Two-year clinical trial: 'Eighth full' can have long-term health effects