Latest news with #intermittentFasting
Daily Mail
27-05-2025
- Health
- Daily Mail
Experts reveal alarming impact of fasting on the body - as gut-wrenching simulation video leaves social media astonished
It's a diet trend endorsed by everyone from Hollywood A-listers to Rishi Sunak. But, to the dread of dietitians across the planet, there's an even more extreme version of 'intermittent fasting' being taken up by those wanting to lose weight—the OMAD diet. An abbreviation for 'one meal a day', the trend does exactly what it says on the tin. Coldplay frontman Chris Martin reportedly swears by it after learning of the diet from legendary rocker Bruce Springsteen, whose wife is a proponent. Yet experts have urged caution over its 'short-lived' effectiveness, warning it could trigger chronic health issues like digestive conditions and even life-threatening heart disease. It comes as an illuminating video posted online this week garnered thousands of views for its alarming display of exactly what happens to the body —hour by hour— when fasting. The four-minute gut-wrenching simulation claimed the body stops digesting food after just four hours, entering what is known as the catabolic phase—when muscle and fat is used for energy. By 12 hours, it has hit a 'fasted state' depleted of blood sugar. Here, the liver begins to break down stored fat into fatty acids called ketones to use as fuel. But ketones can be dangerous—high levels of them in the blood can lead to a condition called ketoacidosis, when blood becomes too acidic. If not treated promptly it can be life-threatening. Studies have also found that prolonged exposure to ketones can be detrimental to the heart, increasing the risk of heart attacks and strokes. Fasting up to 16 hours can then stimulate autophagy— where cells break down and remove damaged or unnecessary components like old proteins—it is claimed. Research has long warned, however, that excessive or prolonged autophagy can lead to cell death, potentially harming organs. Supporters of OMAD say it can boost productivity, improve memory and cognition, helps them manage their weight easier and keep fit. OMAD was made famous by model-turned-actress Liz Hurley in the early 2000s, who was admired for her age-defying figure which inspired envy in women in their 20s. The now 57-year-old admitted to limiting herself to just one meal per day after giving birth to her son Damian in 2002, confessing that she was 'going to bed hungry'. Other intermittent diets, such as the 16:8 eating plan, are based on entirely the same principal. But followers instead fast for 16 hours a day, and eat whatever they want in the remaining eight hours — typically between 10am and 6pm. This can be more tolerable than the infamous 5:2 diet, where calories are restricted to just 500 a day twice a week. By creating a calorific deficit during fast days, the body instead relies on breaking down stored body fats to to create energy, aiding quicker weight loss. But sports nutritionist Abigail Roberts told MailOnline: 'Unless the meal contains all the necessary nutrients and calories required by the body, it's unlikely to be a healthy approach to eating, especially if done over a long period. 'Research has shown that consuming only one meal a day can lead to inadequate nutrient intake, causing deficiencies that may lead to various health problems such as fatigue, weakened immunity, and impaired cognitive function. 'Additionally, eating one meal per day may increase the risk of binge eating during that meal, causing digestive discomfort such as bloating and constipation.' Intermittent fasting does have benefits 'for some people', Miss Roberts accepted. But she urged anyone looking to drastically cut weight — a theme at this time of the year when many are trying to get in shape for summer — to inform their doctor. Dietician and spokesman for the British Dietetic Association, Dr Linia Patel, also told MailOnline: 'Whatever weight loss or health benefits you see on the OMAD diet will likely be short-lived. 'Not eating for 23 hours will likely lead to a lack of energy, fatigue, uncontrollable cravings, and disruptions to your bowel habits.' She added: 'This diet is not one I would recommend as it is too restrictive, can lead to fad dieting and disordered eating. 'There is some positive research surrounding fasting in general, showing that fasting when done in the right context could aid in weight loss and assist in preventing chronic disease, 'If you do want to try intermittent fasting, at least go with the 16:8 method, which has you fasting for 16 hours and eating for eight. It's not for everyone, but it's a much more balanced approach. Speak to a dietitian for more tailored support.' Professor Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, said: 'Any mechanism that helps people control their calorie intake will help them lose weight — the key issue is whether one meal per day is sustainable in long term.' He told MailOnline: 'It may not be for the vast majority of people. Rather small sustained changes in usual caloric intake with three meals per day maybe a better achievable goal for many.' Research into OMAD specifically is still emerging. One 2022 study, however, found participants who only ate one meal per day saw a greater reduction in their body weight and fat mass. There was no difference in lean mass or bone density by the end of the 11-day trial, however, according to results of the 11-person project in the journal Frontiers in Physiology. A second study a year earlier in the Journal of Animal Science and Biotechnolog y compared the effects of eating one large meal a day against two or six in mice. Rodents on just one meal gained more weight than those who consumed multiple meals. Writing for The Conversation, Dr Amanda Avery, an associate professor in nutrition and dietetics, at the University of Nottingham also said: 'There's still a lot we don't know about it.' She added: 'It's also important to note that while this diet might work for celebrities, they also have access to nutritionists, high-quality diets and supplements where needed. 'For most of us, this kind of diet could be unsustainable – and potentially harmful in the long run.'
Health Line
22-05-2025
- Health
- Health Line
What to Know About Alternate Day Fasting
Alternate-day fasting may help promote weight loss and may help lower risk factors related to heart disease and type 2 diabetes. Alternate-day fasting is one way to do intermittent fasting. On this diet, you fast every other day but eat whatever you want on the non-fasting days. The most common version of this diet involves 'modified' fasting, where you can eat around 500 calories on fasting days. Here's a detailed beginner's guide to alternate-day fasting. How to do alternate-day fasting Alternate-day fasting (ADF) is an intermittent fasting approach. The basic idea is that you fast on one day and then eat what you want the next day. This way, you only need to restrict what you eat half of the time. On fasting days, you're allowed to drink as many calorie-free beverages as you like. Examples include: If you're following a modified ADF approach, you're also allowed to eat about 500 calories on fasting days, or 20–25% of your energy requirements. The most popular version of this diet is called 'The Every Other Day Diet' by Dr. Krista Varady, who has conducted most of the studies on ADF. The health and weight loss benefits seem to be the same regardless of whether the fasting-day calories are consumed at lunch or dinner or as small meals throughout the day. Some people may find that alternate-day fasting is easier to stick to than other types of diets. However, a yearlong study found that adherence to alternate-day fasting (where calorie intake was reduced to 25% of energy needs on fasting days) was not superior to everyday calorie restriction. Most studies on alternate-day fasting used the modified version, with 500 calories on fasting days. This is considered much more sustainable than doing complete fasts on fasting days, but it's just as effective. In this article, the terms 'alternate-day fasting' or 'ADF' generally apply to the modified approach with about 500 calories on fasting days. Alternate-day fasting and weight loss Although ADF may help promote weight loss, studies have suggested that this type of calorie restriction is no more effective for weight loss than traditional daily calorie restriction. Studies among adults with overweight and obesity show that engaging in ADF may help you lose 3–8% of your body weight in 2–12 weeks. Research suggests this method is not superior to traditional daily calorie restriction for promoting weight loss. Although ADF may offer benefits for fat loss, research shows that ADF is no more effective than traditional calorie restriction for promoting weight loss or preserving muscle mass. Furthermore, like other types of calorie restriction, weight loss during ADF may be accelerated when combined with increased physical activity. For example, combining ADF with endurance exercise may cause twice as much weight loss as ADF alone and six times as much as endurance exercise alone. Regarding diet composition, ADF seems to be equally effective whether it's done with a high or low fat diet. Alternate-day fasting and hunger The effects of ADF on hunger are somewhat inconsistent. Some studies show that hunger ultimately goes down on fasting days, while others state that hunger remains unchanged. However, research agrees that modified ADF with 500 calories on fasting days is much more tolerable than complete fasts on fasting days. One study comparing ADF to calorie restriction showed that ADF increased levels of brain-derived neurotrophic factor (BDNF) after 24 weeks of follow-up. BDNF is a protein that plays a role in energy balance and body weight maintenance. Researchers concluded that ADF may induce long-term changes in BDNF and that this may promote improved weight loss maintenance. However, the researchers found that BDNF levels did not correlate with body weight changes in this particular study and suggested that these findings be interpreted with caution. Human studies have not shown significant effects of ADF on hunger hormones. Another factor to consider is compensatory hunger, which is a frequent downside of traditional daily calorie restriction. Compensatory hunger refers to increased levels of hunger in response to calorie restriction, which cause people to eat more than they need to when they finally allow themselves to eat. Studies have shown that ADF doesn't seem to increase compensatory hunger. In fact, many people who try modified ADF claim that their hunger diminishes after the first 2 weeks or so. After a while, some find that the fasting days are nearly effortless. However, the effects of ADF on hunger most likely vary by individual. Alternate-day fasting and body composition ADF has been shown to have unique effects on body composition, both while you're dieting and during your weight-maintenance period. Studies comparing traditional calorie-restricted diets and ADF show they're equally effective at decreasing weight and fat mass. Some studies have suggested that ADF may be more beneficial for preserving muscle mass than other types of calorie restriction, However, results from a 2016 study suggest that ADF is no more effective for preserving muscle mass than traditional calorie restriction. Health benefits of alternate-day fasting ADF has several health benefits aside from weight loss. Type 2 diabetes Type 2 diabetes accounts for 90–95% of diabetes cases in the United States. What's more, more than one-third of Americans have prediabetes, a condition in which blood sugar levels are higher than usual but not high enough to be considered diabetes. Losing weight and restricting calories is usually an effective way to improve or reverse many symptoms of type 2 diabetes. Similarly to continuous calorie restriction, ADF seems to cause mild reductions in risk factors for type 2 diabetes among people with overweight or obesity. ADF may also help reduce fasting insulin levels, with some studies suggesting that it may be more effective than daily calorie restriction. However, not all studies agree that ADF is superior to daily calorie restriction. Having high insulin levels, or hyperinsulinemia, has been linked to obesity and chronic diseases, such as heart disease and cancer. Reducing insulin levels and insulin resistance should significantly reduce the risk of type 2 diabetes, especially when combined with weight loss. Heart health Many studies have shown that ADF is a good option to help individuals with overweight or obesity lose weight and reduce heart disease risk factors. The most common health benefits include: Alternate-day fasting and autophagy One of the most common effects of fasting is the stimulation of autophagy. Autophagy is a process in which old parts of cells are degraded and recycled. It plays a key role in preventing diseases, including cancer, neurodegeneration, heart disease, and infections. Animal studies have consistently shown that long- and short-term fasting increase autophagy and are linked to delayed aging and a reduced risk of tumors. Moreover, cell studies have confirmed that fasting stimulates autophagy, resulting in effects that may help keep you healthy and live longer. This has been supported by human studies showing that ADF diets reduce oxidative damage and promote changes that may be linked to longevity. The findings look promising, but the effects of ADF on autophagy and longevity need to be studied more extensively. Does alternate-day fasting induce starvation mode? Nearly all weight loss methods cause a slight drop in resting metabolic rate. This effect is often referred to as starvation mode, but the technical term is adaptive thermogenesis. When you severely restrict your calories, your body starts conserving energy by reducing the number of calories it burns. This can cause you to stop losing weight and feel miserable. However, ADF doesn't seem to cause this drop in metabolic rate. One 8-week study compared the effects of standard calorie restriction and ADF. The results showed that continuous calorie restriction significantly decreased resting metabolic rate compared to ADF. Is it also suitable for people who are within a normal weight range? ADF is not only beneficial for weight loss, but it can also offer health benefits for those who don't have obesity. A 3-week study analyzed individuals with average weight following a strict ADF diet with zero calories on fasting days. The researchers found that it resulted in increased fat burning, decreased fasting insulin, and a 4% decrease in fat mass. However, hunger levels remained relatively high throughout the study. They speculated whether a modified ADF diet with one small meal on fasting days might be more tolerable for people who don't have obesity. Another controlled study involved individuals with overweight and average weight. It showed that following an ADF diet for 12 weeks reduced fat mass and produced favorable changes in risk factors for heart disease. That said, ADF generally provides much fewer calories than you need to maintain weight, which is the reason you ultimately lose weight. If you're not looking to lose weight or fat mass, or have average weight to begin with, other dietary methods will probably suit you better. What to eat and drink on fasting days There's no general rule regarding what you should eat or drink on fasting days, except that your total calorie intake shouldn't exceed around 500 calories. It's best to drink low calorie or calorie-free drinks on fasting days, such as: water coffee tea Some people find it best to eat one 'big' meal late in the day, while others prefer to eat early or split the amount between 2–3 meals. Since your calorie intake will be severely limited, it's best to focus on nutritious, high protein foods and low calorie vegetables. These will make you feel full without many calories. Soups may also be a good option on fasting days, as they tend to make you feel fuller than if you ate the ingredients on their own. Here are a few examples of meals that are suitable for fasting days: eggs and vegetables yogurt with berries grilled fish or lean meat with vegetables soup and a piece of fruit a generous salad with lean meat You can find numerous recipes for quick 500-calorie meals and healthy low calorie snacks online. Is alternate-day fasting safe? Studies have shown that alternate-day fasting is safe for most people. It doesn't result in a greater risk for weight regain than traditional, calorie-restricted diets. Some think that ADF increases your risk of binge eating, but studies have found that it may help reduce binge eating behavior and decrease depressive symptoms. It may also improve restrictive eating and body image perception among people with obesity. However, more research on the effectiveness and safety of ADF in people with disordered eating tendencies is needed. That said, ADF is likely not appropriate for certain populations. These include children, pregnant and lactating women, people who are underweight, and those with certain medical conditions that may be exacerbated by fasting, like Gilbert Syndrome. Although some research suggests that ADF may help reduce symptoms of binge eating, this dietary pattern is likely not appropriate for people with eating disorders, including anorexia nervosa or bulimia. Be sure to consult a healthcare professional before trying this eating pattern if you have a medical condition or are currently taking any medications.
South China Morning Post
21-05-2025
- Health
- South China Morning Post
Rely on science, not fads, for weight loss
The global surge in the number of people who are overweight or obese has rightly focused attention on the need to adopt a healthy lifestyle. But at a time when we are increasingly bombarded with advice on what to eat and drink, many turn to fad diets in a bid to lose weight or gain other claimed health benefits. A study conducted by the Hong Kong Nutrition Association in recent months suggests a surprisingly high proportion – about 40 per cent – of Hong Kong people have tried such diets. More than half of those that did opted for intermittent fasting, which involves skipping meals, and 43 per cent adopted a low-carbohydrate diet. Their motivations were primarily a desire to lose weight or to be healthier. But the association has warned, with good reason, that such diets are often not backed by sufficient scientific evidence and can be counterproductive, leading to other health problems. It is worrying that more than half of the respondents had used unverified information on social media. More than 40 per cent sought advice from friends or relatives.
South China Morning Post
19-05-2025
- Health
- South China Morning Post
Are weight loss diets like fasting, low carbs harmful? Hong Kong experts weigh in
The Hong Kong Nutrition Association recently warned against the growing popularity of restrictive diets such as intermittent fasting and low-carbohydrate meals for weight loss. It followed a survey that found 40 per cent of respondents had experimented with such methods, often based on unverified information from social media and personal networks. Here, the Post unpacks the findings and what adverse health effects nutritionists have cautioned about, as well as what they believe are more sustainable and evidence-based strategies for weight management. 1. What are intermittent fasting and low-carb diets? Intermittent fasting is an eating pattern that cycles between periods of eating and voluntary fasting on a regular schedule. Popular types include the time-restricted eating approach, such as the 16:8 method, where dieters eat within an eight-hour window of the day, while the remaining 16 hours are for fasting. This often meant dieters skipped a meal or two. Some dieters may also choose to alternate between days of normal eating and days of very low calorie intake of about 500-600 calories, or complete fasting. Others may fast for full days once or twice a week.
South China Morning Post
18-05-2025
- Health
- South China Morning Post
Why alternative diets like fasting, low carbs, don't work: Hong Kong nutritionists
The effectiveness of intermittent fasting, low-carbohydrate meals and other alternative diets to lose weight is not backed by enough scientific evidence and could backfire, Hong Kong nutritionists have warned after conducting a survey that showed 40 per cent of respondents had tried such methods. The Hong Kong Nutrition Association revealed on Sunday findings of a survey it conducted between March and the beginning of May, in which 364 respondents, or about 40 per cent of the 916 in total, had attempted at least one of a variety of dieting methods. It added that the residents polled obtained dietary information from possibly unreliable sources, with more than half accessing unverified sources from social media, and over four in 10 from friends and family. Among respondents who went on diets, 51 per cent had tried intermittent fasting, which involves eating once in eight hours and fasting for the remaining 16 hours, while 43 per cent had gone on diets with a low level of carbohydrates. Weight control and improving their health were the key reasons for going on diets, as indicated by 76 per cent and 56 per cent of respondents, respectively. But the association said the effectiveness of such diets was not backed by sufficient scientific research and could lead to adverse health effects. 'Refraining from consuming carbohydrates can slow down metabolism rate, worsen memory, [cause] low energy, low blood sugar and low spirit,' Leona Leung Yuen-ling, the association's vice-president, said.
