We don't just want it, we want it now.
In the modern world, instant gratification is no longer the desirable ideal, it is the norm. From where you sit, you can watch almost anything ever recorded at the click of a mouse, you can buy anything you like and get it tomorrow, and if you order a pizza and it doesn't take under half an hour, you don't pay a penny. It's convenient and it's how we like it.
Taking this into account, it's hard to blame us when we aren't happy to always take the moderate approach to fat loss. We want abs yesterday and the suggestion of taking your time seems almost alien. Just take a look around you. You'll see magazines promising 6 week abs, diet shakes and pills, cereals that can cut a dress size off you in a month, and books telling you not to eat for two days of the week.
We think "ah it's ok, I can put up with it so long as it works. No pain no gain!"
Clearly, this is something that effects a lot of people.
But is it a good idea? You'll usually hear two sides, one saying that it's great and will help you look awesome on the beach in no time, for 5 easy payments of £9.95, and the other side telling you that all of your muscle will evaporate and you'll never have a sex drive again.
Well, in truth, there are both pros and cons to crash dieting which both need to be addressed if you are going to make an educated decision. To keep things positive I'll start with the pros.
The main benefit of 'crash dieting' is that it's incredibly motivating. We all love to talk about looking long term but it's impossible to ignore the fact that it sometimes feels hard to continue with the plan when your weight hasn't moved this week, or it's crept in the wrong direction. With a properly managed very low calorie plan you will see changes on a daily basis, which is very motivating in an of itself. Another positive along these lines is that there is a very clear and close-by end point. A long diet of 1-2 lbs per week can take over half a year of dealing with hunger and feeling lethargic to lose 5 stone, contrast to a much shorter period of crash dieting. This weight loss, provided you know what you are doing, can be maintained effectively (1), and is therefore SOMETIMES a viable option.
Think of it like an Elastoplast. Pulling it off is going to hurt no matter what - fast hurts more for less time, slow hurts less for what seems like an age. Your personality type dictates which one is preferable to you.
This comparatively short amount of time dieting allows for more time training and eating for performance or muscle gain. 12 months of slow dieting is 12 months in which your muscle mass isn't going to get much greater, which is a lot of wasted time if your goal is to carry appreciable muscle mass!
The final pro is that, if done properly, fast dieting is physically harmless in the long term, but may actually be the most effective method in the obese (2). But it MUST be done properly. More on this below.
So far it sounds pretty damn good! Unfortunately it's not all so peachy and, as with anything good, there are a hell of a lot of things one must take into consideration.
Dieting on very low calories is the method of fat loss which carries the greatest risk of muscle loss, without doubt. Your body works on a fine balance, with muscle being broken down and built up 24/7 at varying rates and the final balance of this activity dictating muscle mass changes. When in an extreme calorie deficit it's very easy for breakdown to exceed creation over time - meaning you lose both strength and size quite easily if the diet is prolonged. Combatting this is vital if you intend to try it out, but the sad fact is that, realistically, complete prevention is all but impossible for most. This means that on a very low calorie plan, you WILL lose muscle. Bear this in mind.
Nutritional deficiency is quite likely with this sort of plan. It's incredibly difficult to consume sufficient protein, micronutrients and essential fats as you need for basic health and hormonal function when you are eating less than the average housecat. In medical settings you require close monitoring when put on a diet providing fewer than 1200 calories, but most crash dieters do this in their own home without any medical supervision. You probably know somebody close to you that's lived on cabbage soup or similar for extended periods - it's a recipe for disaster.
Issues such as organ failure, blood sugar related unconsciousness and seizures, hair loss and other horrendous complications are associated with very low calorie dieting - so be VERY mindful of how you are feeling, and seek medical attention if considering this approach, BEFORE you start.
Of course it can't be ignored that you will also feel like crap. Absolute crap. Your body seeks what is known as homeostasis, which means it tries to fight against change. The bigger the change, the stronger the fight. One way in which your body seeks homeostasis in this context is that it reduces sympathetic nervous system output to try to save energy. This causes reduced muscle tone, less general energy and slower thought processing as well as tiredness and irritability. It can also down regulate sex hormone production for the duration of the diet (and possibly longer if you are dieting for a very long time) meaning no libido, possible erectile dysfunction and missed periods in men and women respectively.
Your metabolic rate may also take a hit. As well as reducing the amount you move, your body is capable of reducing your calorie burn at rest by dropping your core temperature amongst other things. This slows down your progress, meaning you have to suffer for longer. The effects reverse very quickly when you increase calories again, but it sucks for the time you are dealing with it.
Reducing your calorie intake increases the release of the hormone ghrelin amongst a few others. These hormones are the chief trigger for HUNGER, meaning that as soon as the diet ends you will be driven to eat more than you need, so the 'rebound' period can be rough, as well as you having an increased risk of binging whilst the diet is still in full swing when you cave in and eat a box of cereal in the middle of the night. This is one reason why a lot of people yo-yo diet terribly throughout life.
Loose skin. Your skin is an elastic organ, but it's 'snap back' quality can only go so far. Gradually losing weight gives your skin the best chance of almost complete recovery.
*Note - if you lose a LOT of weight, there is a chance that you'll have loose skin no matter what you do. Staying hydrated and consuming a varied, predominantly whole food diet gives you a fair shot, but even then you stand the chance of falling short. This is unavoidable if your skin genetics deem it so.
Surgery is an option, but the best thing to do is minimise it in the first place by dieting slowly.
The final downside to this dieting technique is the most important, and that is the mental side of things. This dieting technique doesn't teach you any healthy habits, if anything it teaches that starvation is the way to health - which it simply isn't. By not learning habits of a healthy eater, it's very difficult to sustain the fat loss you have achieved.
How do you eat?
What if you go off track?
What if you go away?
These questions remain unanswered, leading to the typical YOYO dieting pattern seen in so many crash dieters.
But more sinister is the way this kind of diet can affect your relationship with food. Food is something which should be enjoyed, providing pleasure as well as sustenance. Unfortunately all you learn from a very low calorie diet is that eating makes you fat and starving makes you lean. If you don't want to eat again because you are scared that you will gain bodyfat, you have a problem.
This happens a lot. Crash dieters are sometimes referred to eating disorder patients in training, with a huge number of anorexics or binge eaters coming from crash dieting backgrounds. For this reason alone, I generally advise against low calorie plans entirely.
So, my practical recommendations,
Don't crash diet, just don't. Take your time to learn your body and how it works. Learn how to eat in a sustainable manner that you enjoy and can afford but which is in line with your goals.
Forget the idea that dieting needs to be hard and painful. Taking a flexible approach to your food choices means that you can enjoy the foods which you choose whilst still reaching your goals - social life and sanity in tact! Also forget the idea that slow dieting truly is slow.
Just think, if you start today you will look dramatically different in 6 months time. That's a lot less time than you think it is.Tweet
But what if you're dead set on trying a crash diet?
It's unfortunate but I know that some of you reading this are going to crash diet anyway, for holidays or other events, or even as a 'kickstart' to a regular diet, so if it's going to happen please at least follow this advice so you are safe.
1 - Don't do it
2 - Ok, if you're still here. Don't do it until you have a good set of healthy eating habits. This is incredibly important and I would seriously ask anyone reading this not to skip this step. Fast dieting is for those who know what they are doing, as a kickstart to a long and slow diet (crash 1-3 weeks, diet for another 3-6 months) or as a method of 'damage control' during a lean gaining phase. If you are in the position of being a total novice, you WILL NOT keep your fat loss, and due to the rebound effect mentioned above WILL gain it all back plus more. This is not a scare tactic, it's a fact. Learn to eat healthy by the book before bending the rules. As a rule of thumb, if you haven't been "eating properly" for at least a year (meaning meals on a regular schedule, mostly whole foods, a good handle on your calorie and macronutrient intake, no binges, no food guilt), then wait. Your progress when implementing these steps will dramatically outstrip the temporary results you'd get in a few weeks.
3 - Take care of your recovery from training. You are going to struggle to consume enough minerals such as Zinc and Magnesium, meaning your training will go down the pan. Combatting this is important if you are to maintain energy levels and performance.
4 - Learn how to do it properly. There are crash diets out there which WILL cause harm and/or poor results. There are also methods of doing this right. Lyle McDonald has written on this subject and researching him and his work needs to be point of call number one.
5 - Just don't do it. Hire a coach. Trust me, the suffering is not worth speeding things up by what is, realistically, 4-6 months, or maybe 2 years if you are very overweight. This amount of time is nothing in comparison to your life, and I've never spoken to anyone who lost over 10 stone in two years (just one-two pounds per week) who regrets it, yet half of my business is 'fixing' ex crashers.
(1) Katrina Purcell et al. The effect of rate of weight loss on long-term weight management: a randomised controlled trial. The Lancet Diabetes & Endocrinology, 2014
(2)Casazza, K et al. ‘’Myths, Presumptions, and Facts about Obesity’’ NEJM, 2013