Extreme Calorie Restriction Diets – Do they Work and What are the Risks?
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As far as weight loss trends go, the recent fascination with extreme calorie restriction diets (CR Diets), like Lighter Life and The 21-Day Fix, have been thrown into the spotlight due to their very low energy intake limits, of between 500 and 1000 calories per day.
In order to maintain status quo, the Australian Dietary Guidelines from the Dieticians Association of Australia recommend that:
- Adult males should consume a daily calorie intake of 2,500 to maintain their weight
- Adult females should consume a daily calorie intake of 2,000 to maintain their weight
This is considerably higher than the 500 – 1000 daily calorie count for CR diets. Supporters of these plans claim, they are meant for the short term only, are effective and safe making you thinner in the short term. Critics say that CR diets are dangerous, encourage crash dieting, fasting and, even in some cases, behaviour more commonly associated with disordered eating such as binging and starvation.
What is an extreme calorie restriction diet (CR)?
A CR diet, such as the 21 Day Fix, claims to be able to help followers lose up to 7kgs in 3 weeks. This particular diet claims to work because it only takes 3 weeks to see evidence. It combines portion control, colour-coded and pre-weighed meal planning, meal replacement shakes, exercise and significant calorie restriction in order to achieve high levels of weight reduction in 21-days.
In order to calculate how much you can eat in a day, you are supposed to apply a formula for your specific calorie intake. This is done by multiplying your weight by 11 and adding 400 (to represent the calories burned in your daily exercise workout). The result is your daily calorie intake goal to;
Eg: 80kg x 11 + 400 (calories Burned) = 1280 Calories per day
You need to subtract 750 – this is the total amount of calories you eat per day during the 21-day programme.
Eg: 80kg x 11 + 400 (calories Burned) = 1280 – 750 = 528 Calories per day.
Do extreme calorie restriction diets work?
Any eating regimen which sees you reduce calorie consumption and increase physical activity will result in weight loss. So the short answer is yes – but only for as long as the regimen lasts, and as soon as your caloric intake is increased with your exercise level reducing, your weight loss will be cancelled out as you will gain back what you have lost – and possibly even some more.
In addition, meal plans for CR programmes are expensive and time consuming, with very small portions of food. The amount of pre-planning and willpower required might be beyond most of us for 21-days!
What are the health risks?
Severe Calorie Restriction Diets (CR Diets) like the 21-Day Fix, Lighter Life and the HCG (Human Chorionic Gonadotropin) method pose serious health risks, when calorific consumption is less than 1,100 per day.
Sometimes these diets allow for only around 500 to 800 calories per day, which the University of Maryland Medical Centre in America has cautioned as being unsuitable for longer than 6 weeks at a time.
According to the Mayo Clinic, some other specific health risks of CR diets include:
- Hair loss
- Bone density loss
- Muscle loss
- Electrolyte imbalance
- Mineral and vitamin deficiencies
- Difficulty concentrating
- Menstrual disturbances for women
- Low sodium levels in the blood (hyponatremia)
- Possible death
Choose a better, healthier and longer term way to lose weight
Heath experts are in agreement that Calorie Restriction Diets are short-term fixes only. There are a lot more consistent and less health-damaging ways to lose weight safely, the most important way is to have a well-balanced diet.
In order to find out how many calories your body truly needs in order to maintain, or lose your weight use this calculator.
Variety and balance are the spice of life
Focus on long-term weight loss goals and a healthy, balanced diet of fruits, vegetables, whole grains, low-fat dairy or dairy-alternative products, lean proteins, pulses, nuts and seeds. And do not forget that not all fat is bad fat – olive, avocado and coconut oils are great and can even help your body burn fat more efficiently. Always consult with your physician before embarking on a new health kick, especially if you are pregnant or about to undergo surgery at one of our clinics.
Alternatively, you can speak to one of our health advisors by calling (03) 8849 1444.