Hi:

I am seeing much more confusion between doing 5:2 and ‘fasting’. Another way to put it is confusion between severe calorie restriction and the length of time between eating. For the record, it is the severe calorie restriction twice a week that leads to weight loss when following 5:2 (and, perhaps, other ‘health benefits’), not the time between eating.

5:2 was born from a documentary Dr. M did on calorie restriction and life extension (not weight loss). Only one of the four basic segments of the show was on fasting. That segment was all about a four day fast that yielded good blood work results (‘fast’ meaning eating no food for four days) . However, the researcher involved said that to continue benefiting, you would have to do four day fasts monthly (I’m going from memory), and Dr. M decided that he could not do fasts that often even if he did get the positive results.

Another segment was on a man that had been eating 1900 calories a day for over 10 years. He weighed 134 pounds and was in excellent health. Dr. M decided he could not do that, either. A third segment was on ADF – alternate day fasting – where people alternated between eating 500/600 calories one day and eating what they wanted the next. That approach yielded good blood work and weight loss results regardless of what people ate on their non diet days. The fourth was on calorie restriction and Alzheimer’s. Initial research on animals indicates severe calorie restriction can delay its onset

At the end of the show, in consultation with the researchers, Dr. M came up with what we now know as 5:2 and decided to try it for five weeks. It worked for him, yielding good blood work results. The show noted as an aside that Dr. M lost weight. After it was aired, people tried 5:2 (presumably for the potential health benefits) and began losing weight. Recognizing a good thing when it appeared, Dr. M quickly wrote a weight loss diet book (not a life extension diet book), and the rest is history.

The point is 5:2 is about calorie restriction, not fasting in the sense of time between meals. To explain, I see people not eating (fasting) for 24 hours (say, 2 pm to 2 pm the next day) and thinking they will automatically lose weight. But they eat their TDEE before 2 pm (because they will not be eating for a ‘day’) and eat their TDEE after 2 pm the following day (because they are hungry), often with 500/600 calories in between. There is no calorie restriction, they do not lose weight, and they quit because ‘it does not work’. It is the same for 16:8, don’t eat until 5 pm or any other ‘time between eating’ diet plan. They can work, but only if you count your calories and make sure you eat under your TDEE every day. They are reduced calorie diets, that do not have the potential health benefits that come from severe calorie restriction, using an IF (‘Intermittent Fasting’) label. I have nothing against any weight loss diet ‘that works for you’, but this is the 5:2 site, so I am focusing here on how ‘the real 5:2’ works (not options or off-shoots).

So if you are a newbie here because you want to try 5:2, I recommend you start by doing 5:2 correctly for at least two months before you start thinking of doing something else.

‘Doing 5:2 correctly’ means going to bed, getting up, eating 500/600 calories while you are awake, going to bed, getting up and eating normally – twice a week. ‘Normally’ means eating your TDEE or less. Here is what you need to know about TDEE: http://thefastdiet.co.uk/forums/topic/tdee-for-the-curious-or-why-dont-i-lose-weight-faster/. And here are some general tips for those just starting: http://thefastdiet.co.uk/forums/topic/warnings-to-newbies/.

There are tens of thousands of people quietly being successful with 5:2. The ones who are not being successful generally are simply eating too much on their non-diet days (and often their diet days, too). It makes no difference if you eat a (small) breakfast, lunch and/or dinner on your diet days, eat only one meal or don’t eat anything, because time between meals is irrelevant. It is the severe calorie restriction twice a week that counts!

Good Luck!

Vivalas:

You are doing 5:2.

The next challenge may be your pattern of weight loss. This might help: http://thefastdiet.co.uk/forums/topic/really-no-weight-loss/

Good Luck!

Hi Nina:

Conceptually, calories are a zero sum game. If you don’t eat for a long enough period of time (and this varies by individual), you will burn fat to keep going. But then you eat, and if you have calories you don’t need at the time, they go to fat and you are where you would have been anyway.

Having stated the theory, recent research (that needs to be confirmed) indicates that the fewer times you eat a day, the better the weight loss and blood work results, at least for people with type 2 diabetes. One group ate six times a day, another two times a day. The nutritional and caloric intake of the two diets was identical. After three months, the two groups switched diets and went for another three months. The results were that the two meal a day group(s) lost more weight and had better blood work results than the six meal a day group(s). http://www.diabetologia-journal.org/files/Kahleova.pdf. There is much interesting there, including the fact the groups ate identical diets but the two meal a day groups lost materially more weight.

Here is an interesting quotation from the study:

“Our results are in strong agreement with animal studies,
which have demonstrated the glucose-lowering effects of
intermittent fasting regimens (such as every other day fasting
or fasting for 2 days a week). These regimens reduce blood
glucose and insulin concentrations, improve glucose tolerance
[4, 28], mainly due to increased insulin sensitivity [29], and
extend the lifespan of laboratory animals [30].

Our data contradict the widely held opinion that eating
more frequently is healthier than eating less frequent larger
meals.”

This would seem to suggest that there is some benefit to somewhat extended times between meals on a daily basis (as suggested by concepts like 16:8 – or just skipping some meals). This area of research is rapidly expanding, and I suspect we will be hearing much more on the subject over the next few years.

Hi Dummerchen:

There is some evidence that some foods take more calories to burn than others, and that the body treats carbs differently than fat and protein. For instance, we now recognize that carbs are digested and converted to blood sugar quite quickly, and if they are not immediately used via physical exertion, are deposited as fat. Unfortunately, this leaves the person hungry and they eat even more. The obesity epidemic, as it is called, looks like it may be caused by the low fat, high carb diet.

I am not familiar with any studies showing excess caloric intake not leading to weight gain because of the food being eaten. If you have any links to such studies, I would be interested. As far as I know, the current studies on foods causing metabolic increases are pretty much stymied because the amount of increase, if any, simply can’t be measured with today’s technology.

However, I am familiar with studies on high fat/protein diets. One in particular (that I participated in) required people to eat 20 grams or less of carbs, daily, for several months. But the participants could eat as much fat and protein as they wanted. The participants lost weight like crazy, (some two or more pounds a week), even though they could eat all the non carb containing foods they wanted (no alcohol, though). The people kept detailed, daily food diaries.

The food diaries were kept to keep track of carb intake, but when they were analyzed for caloric content, the results were shocking. It turned out that even though the people could eat as much fat, meat, eggs and cheese as they wanted, and because of that were never hungry, their daily caloric intake was around 1200 calories a day. They lost weight because they were not consuming very many calories, not because the foods they were eating caused a metabolic increase.

The non scientific way to explain why eating fat and protein can cause weight loss and eating carbs may not is to think of a fast acting pill versus a timed release pill. Carbs are fast acting (as most athletes that carbo load before their activity know). Carbs create blood sugar quickly and provide quick energy. When that blood sugar is not used quickly, however, it is also quickly deposited as fat. The result is low blood sugar and hunger (sugar high, low sugar crash).

Fat and protein are digested by the body much more slowly (leading some to suspect it takes more energy to digest them). They provide a much lower and much more constant supply of blood sugar to the body. As a result, eating fat and protein satisfies hunger for longer periods of time and people eat less because they are not hungry.

Many people on 5:2 soon recognize this in regards to their diet days. They often decide that the food they eat on their diet days should be high protein/higher fat because they find they are less hungry when they eat those kinds of foods. Many people are also surprised that they are not starving when they wake up after their diet day. By that time, most are feeding off their own fat and do not need to have their blood sugar supplemented by eating food.

Sorry for the non-scientific science lesson, but it is quite an interesting topic that most people on any diet can benefit from.

Hi takloo:

Congratulations on your progress!

The numbers you have given would indicate that if you were eating to your TDEE (and I know you said you were not) you could expect to lose about 3/4 of a pound a week. The fact you have lost over two pounds a week is probably a combination of eating less on your non diet days and water weight loss.

I’m responding because you say you will only believe 5:2 works if you lose about a pound a week (or more) over the next 6 to 8 weeks. I certainly hope you do, and that is certainly possible, but don’t be surprised if you hit a ‘plateau’. If you do I recommend you not quit, because you have already proven you can lose weight following 5:2. Sorry to say, 5:2 comes with no promises of how fast or how consistently any given individual will lose the weight.

Good Luck!

Hi takloo:

Water loss is not bad or good. Your body has different water needs over time an retains or expels water to match those needs. Many people on starting a diet lose quite a bit initially, and hope that rate of loss continues. They become disappointed when it does not. The fact is it is hard to lose a lot of fat weight rapidly. To lose two pounds of fat weight a week consistently, a person has to cut 1000 calories a day from their diet. That would mean you would have to average eating 1000 calories a day to lose two pounds a week, given your TDEE of 2000.

A second way to do it is for a person to increase their exercise substantially. However, that carries two challenges. First, it takes a lot of exercise to equal a pound of fat loss a week (I have to run over 18 miles to burn a pound of fat), and second, if you start exercising a lot more than you have been your body retains water to help repair and strengthen the muscles you are using. The water retention masks the fat loss and it looks like you are not making progress. Both lead to unhappiness when people fail to lose weight as quickly and as much as they feel they should, given their hard work of both being on a diet and exercising a lot more than they used to.

When it comes to weight loss, life just isn’t fair.

takloo:

‘question – does not eating BMR / TDEE calories on feed days affect weight loss adversely’

There is no research that indicates that eating fewer calories will lead to slower weight loss. The fastest way to lose is to eat nothing (not recommended). You seem to be proving that eating less is causing more weight loss.

I’m not sure why you want to weigh 132 pounds, but Good Luck!

takloo:

Clothes off.

Fitbug:

No pain, common questions.

‘Doing 5:2 correctly’ means going to bed, getting up, eating 500/600 calories while you are awake, going to bed, getting up and eating normally – twice a week. ‘Normally’ means eating your TDEE or less.

That means you can eat your 500 calories anytime from when you wake up to when you go to bed. There is no requirement that you wait 24 hours (or any other time period) between meals. Many people eat just one high fat/protein meal in the evening on their diet days because they find if they eat earlier they get hungry before bed. The high fat/protein is most healthy and satisfies their hunger until they wake the next morning.

Also, any two days a week work, so if you miss one day, make it up another.

Good Luck!

Hi Evelyn and welcome:

Perfectly fine.

Good Luck!

Dr. Krista Varady’s recent research seems to address the question of when you should eat on your diet days. Here is her summarization of her research on the topic:

“Quick update: Our “meal timing” study is now finished and the results have been published in the Journal, Obesity. Please find a link to the abstract below…
Results from this study show that people can eat the fast day meal at dinner or as small meals throughout the day and lose the same amount of weight as eating the meal at lunch. This is contrary to what we expected…before the study was complete, we assumed that people would not be able to control their calories if they ate small meals throughout the day. We were wrong!
In short, feel free to spread your fast day calories throughout the day if this works for you.”
http://www.ncbi.nlm.nih.gov/pubmed/25251676

Hi JYHG:

You are mixing apples and oranges. 5:2 is a weight loss diet. As long as you ingest 5/600 or fewer calories on your two diet days each week, you will be following the 5:2 diet. It depends on the calorie content in your juice whether or not drinking it will reduce the effectiveness of 5:2.

Aside from weight loss, if you are concerned about getting into the ‘fat burning’ mode for ‘other health benefits’, then ingesting carbohydrate calories ‘breaks’ the fast, so your juice will stop any progress you might make toward that goal.

Good Luck!