How fast do crash diets work

Crash diets are low calorie diets, and we lose weight when we consume fewer calories than we burn, no matter how weird or sensible the diet. But much of the weight lost on a short term crash diet is fluid.

Very restricted diets, especially those low in carbohydrate, cause the body to use up carbohydrate stores, known as glycogen, in the liver and muscle. Glycogen is stored with three times its weight in water which is also lost, and can lead to a 4 to 5lb loss on the scales in days. But once normal eating resumes, glycogen and fluid are rapidly restored and weight goes back up. A balanced diet includes foods from the four main food groups: fruit and vegetables; breads, potatoes and other cereals; milk and dairy foods; and meat, fish and vegetarian alternatives.

Strict low carb diets lack nutritious foods like wholegrain breads and cereals, fruit, pulses and yogurt, and detox diets which exclude wheat, meat and dairy can be low in iron to prevent anaemia , zinc for healthy skin and immunity and calcium for strong bones. The saving grace is that these diets are so boring and rigid, most people are unlikely to follow them long enough to cause true nutritional deficiencies.

But following them frequently could affect your bone health, and increase the risk of iron deficiency and anaemia which cause lethargy, poor concentration and irritability.

Whenever we lose weight, most of the weight lost is fat but we also lose some lean muscle tissue. This loss can be minimized by combining gradual weight loss with regular physical activity. If your outrage prescription is running low, top yourself up here. The Big Crash Diet Experiment review — does dramatic calorie reduction work? Photograph: BBC. Formula meal diet plan can tackle obesity in short term.

Read more. Reuse this content. But do these diets actually work, and are they even safe? Noble said. Weight lost during a crash diet is likely from lean muscle and water, not body fat, according to the AAFP. When you exercise, the amount of fatty acid utilized by your skeletal muscles increases, which makes it easier for your body to maintain your new, lower weight.

Cleanses can cause some serious health risks. They can deplete your body of vitamins and dehydrate you. They can even lead to heart problems like arrhythmia—an irregular heartbeat. As your visceral fat melts away, your cravings abate — and more weight comes off, and stays off. Those on the calorie diet not only lost weight fast, they were, at the end of a year, on average 10kg lighter. Even more impressively nearly half had restored their blood sugars without the use of medication.

Those receiving standard advice, by contrast, lost on average just over two pounds, and only four per cent of this group had put their diabetes into remission. In , obesity expert Professor Susan Jebb, of Oxford University, authored an extensive report 8 on the best way in which to approach the escalating obesity crisis. The report included the results of a second study, the Droplet trial 9. Like Direct, Droplet tested an calorie regime, lasting eight weeks. Participants then underwent a behavioural support programme.

Although rapid weight loss is not suitable for everyone, Professor Jebb thinks more doctors should be prescribing calorie diets for people in need of dramatic weight loss. So why is rapid weight loss, when done properly, so much more effective than the slow and steady approach that is routinely recommended? According to a recent Australian study 10 , the success of rapid weight loss is largely down to the psychological boost people get from seeing serious results, and seeing them quickly.

Researchers took obese volunteers and put half on a very low calorie diet fewer than calories per day for 12 weeks. The other half cut their calories by a day enough to lose a pound a week for 36 weeks. Frustrated by slow progress, fewer than half of the steady dieters made it to the end. More than 80 per cent in the rapid weight loss programme, however, stuck to it.

Although both groups put some weight back on over three years, those who completed the crash diet did not put on extra weight compared to those who completed the steady programme. Backing up the findings of the Australian study, a review in the New England Journal of Medicine 11 cited four separate studies that linked more ambitious weight-loss goals to better weight-loss outcomes than those achieved by slow and steady programs.

Crash diets have endured a bad rap down the years. And yet the evidence shows that when done properly, with correct nutrition, rapid weight loss diets work. Fast reductions in belly fat, cravings and weight — along with increased levels of alertness and energy — make powerful motivators, leading to the spectacular results of the Direct and Droplet trials.