February 16, 2009

Type 2 Diet Poll Results

UPDATE: Added 7 more data records collected from posting poll of Low Carb Friends discussion board. All statistics were reanalzyed, but the medians did not change.

I also added an analysis of the data from those who maintained weight losses for 5+ years.
I've taken the information contributed by people who responded to the poll in the comments posted to the previous post and done what I could to standardize the responses in a way that makes it possible to analyze this data.

Fifty-one people contributed data. Of these 49 had Type 2, 1 had MODY and 1 had Type 1.

Two reported a weight gain.
One maintained a stable weight for 40 years but is probably not a Type 2.
Three reported no weight loss or a completely regained the weight they originally lost.

Weight Loss
Of those who lost weight and maintained some of that loss, 42 contributed information which allowed me to calculate what percentage of their starting weight they were able to lose and maintain.

The time framee people reported for their diet ranged from 40 years to just started, with a median time of 2 years.

The amount of weight loss that had been maintained ranged from 190 to 6 pounds, with a median maintained loss of 50 lbs.

The percentage of starting weight that was maintained ranged from 50% to 3% with a median maintained percentage of starting weight lost of 20%. The standard deviation of percentage of starting weight lost and maintained, which is a measure of how closely these percentages cluster around the mean was 10.5%. So most people who maintained maintained a weight loss that was between 9% and 31% of their starting weight.

This is probably the most important statistic of all as it gives you a very good idea of what a realistic weight loss is that you can expect to maintain.

People lost weight using a variety of techniques. Cutting back on carbohydrates was the most common. Thirty-eight respondents reported following some form of a Low Carb diet. Thirteen people reported using ketogenic diets--Atkins, Bernstein or under 60 grams a day of carbohydrate. However, it is possible some of the others who merely reported "low carb" diets were also eating ketogenic diets.

Fifteen respondents attributed weight loss to portion control or counting calories. Ten cited walking. Ten cited "exercise." These methods were often combined and occurred with and without carbohydrate restriction. The biggest weight loss was reported by someone who had Gastric Bypass who reports that severe health problems resulted.

Weight Regain
Twelve people reported significant weight regain. In general, the greater percentage of original body weight they had lost, the more they were likely to regain.

What really stands out is that after regaining, the weight at which these dieters who regained weight were finally able to maintain at was very close to a 20% loss from their starting weight.

This suggests very strongly that a 20% loss from starting weight is the most maintainable weight loss for most people.

Long Term Maintainers
There were 13 people who maintained their weight loss for 5 or more years. This is 25% of all people reporting and a remarkably high percentage. This result might be skewed by the self-reporting nature of this survey.

The largest percentage loss (excluding the loss from surgery) was 33% but 7 of the 10 for whom I have weight loss percentage information maintained a weight loss of 20±3 lbs of their starting weight. This is yet another bit of information that points to 20% as the ideal weight loss percentage to shoot for.

Blood Sugar Control
Five respondents out of 44 who had Type 2 reported that their blood sugar control had improved and they could tolerate more carbohydrate. One with IGT reported significant improvement.

Another 4 reported that they could tolerate slightly more carbohydrate.

Thirty-five reported no change in blood sugar control after weight loss with three stating emphatically that it did not help their blood sugar at all or that blood sugar control got worse.

However, the most important statistic relevant to blood sugar control was that all but 7 respondents reported that they continued to control their carbohydrate intake. So reported blood sugar "improvement" in most cases was dependent on continuing to eat a carbohydrate restricted diet, not because of any true change in their ability to metabolize carbohydrates.


These results suggest that a realistic weight loss that you can expect to maintain would be one that ranged between 10 and 30% of your starting weight, with 20% being the most likely maintainable percentage of weight loss.

They also suggest that losing weight will rarely normalize your blood sugar or "reverse" your diabetes. However, if you use a low carbohydrate diet approach of any type, you can expect to improve your blood sugar control if you continue to stick to some form of carbohydrate restriction.

Those who lost weight relying on portion control and/or exercise may also have to maintain those behaviors to retain any improvements in blood sugar control.

There is no clear cut weight loss advantage to any particular diet plan, as far as producing weight loss. Low carb diet plans appear to be somewhat easier to maintain long term if they lower carbohydrate enough to keep blood sugars controlled and avoid the hunger several people reported with higher carbohydrate weight loss diets.

People lost and maintained weight loss for several years on very low carb and moderate carb plans. Weight gain occurred on various plans too, independent of the carbohydrate intake.


Note: Please feel free to continue to contribute data to the poll in the previous blog post. If enough new information comes in, I will reanalyze it.


Anonymous said...

Good analysis of the data. Infact it yielded informative results

Anonymous said...

Agreed, very interesting, though hardly unexpected except by dieticians (grins)

Some of your readers may care to follow this and the following threads


bsc said...

I think this type of poll can be really helpful in countering the medical advice that if you just lose weight, you will fix your diabetes. After all, we know for a fact that diabetes is caused by being fat (NOT). The idea that so many people have lost weight (and 20% is a lot) and did not fix their dysfunctional handling of carbs is not a surprise to me. But I think for many, it will be new information.

While this type of observational case study information is helpful, I do think you need to interpret the results with some caution. This is a biased sample. After all, the respondants are all self-selected and are people still hanging around diabetes and low carb groups trying to improve their conditions. I have to ask whether there is a large group of people that did lose a lot of weight on low fat diets, cured their diabetes and simply don't hang around in these communities anymore. I doubt there are many people like this, but this can bias the results.
Thanks for undertaking this effort, I think it can really help people feel like they are not alone. Many people are struggling to lose weight (with limited results) and yet despite admirable results are not curing their diabetes.

Anonymous said...

I doubt if doctors advise diabetics to lose weight 'to cure diabetes'. In my case none of my doctors did. Perhaps what doctors say is that losing weight helps in the management of the disease. For those who have weight to lose, and insulin resistance to bring down, I think it is a sensible advice. For me, losing weight (or the exercising and diet that caused the loss of weight of about 7 kg, 10% of my original weight) improved my overall health, besides getting rid of the 'dawn phenomena' like high morning fasting readings. Also, my Hb A1c came down from 6 to 5.3 in little over a year. It may be noted that I was, and am, not at all 'low-carbing'.


Anonymous said...

I missed including in my previous comment that I think exercise and dieting are as important as, and perhaps more so than, weight loss in controlling diabetes that is primarily caused by insulin resistance. By now I may have lost all the weight I had to lose, but I continue exercising for its own benefits.


Jenny said...


You must have a decent doctor.

Many people are told by doctors that if they'd just lost 10 pounds their blood sugar would get much better and that if they were a normal weight, they wouldn't be diabetic at all.

I was told that, which is why I spent years trying to get to a completely normal weight. I did, but it made no difference at all in my blood sugars.

That was one of the factors that impelled me to start studying diabetes to find out what the research showed, because so much of what my doctors told me was completely wrong.

Kat said...

This is kinda depressing for someone who is new to this. I am one who was told by my Doctor to diet and exercise due to being pre-diabetic. I've lost 14 lbs in the last 6 months but notice it has nothing to do with my blood counts. The LC does! As long as I don't go over 20 carbs a day, I can do pretty good. I am not on any meds at this time (but plan on asking for them soon to try to regulate my readings).

My last HBC1 was 6.4 and I'm hoping in April it will be in the 5% as I've been reading between the low 90's and about 110 on the average. I still have the morning highs and can't seem to figure out how to bring them down.

Only being able to lose 20% and keeping that off is very depressing for me as I was hoping to be able to get to a normal weight and keep it there...It's not working very well, lol.

Being a novice, all I can sermize from what I have been doing is that the LC is what really works the best. If I go off plan and eat something with high carbs...I spike immediately.

Jenny said...


Trust me, it is less depressing to learn this up front, so you can concentrate on keeping your blood sugars normal and not obsess about weight loss, than it is to do what I did: work for years on trying to get to a normal weight, undergoing all kinds of dietary deprivation, only to get to a completely rock solid normal weight and optimal body fat percentage and see NO DIFFERENCE IN BLOOD SUGARS.

That is depressing. It is a lot easier to control with diet than it is to lose weight and you have less risk of damaging your metabolism and making it much too efficient--which is an outcome that happens if you lose more than 10-20% of starting body weight that means that for the rest of your life you will have to eat less food than you used to.

Anonymous said...

It's really a test of your doctor's competence as to whether they see weight as the *cause* of diabetes or the other way round.

That's why I bang on endlessly about my history. Everyone in the family has *some* symptoms of metabolic syndrome and only a few have actual diagnosable diabetes, going back a couple of hundred years.

Often the people with more symptoms, and the diabetics, are not overweight.

This does not fit the meeja soundbytes "you made yourself fat through sloth and gluttony and that caused the diabetes" but it fits the theory that both Type 2 and obesity are connected to insulin resistance, leptin, etc. etc.

The people who do worse are those who *don't* put on weight as the glucose is not stashed and hangs around in the bloodstream driving up the lipids and causing other mayhem. The ones who *can* deposit it as fat have much better BP and lipids and aren't diabetic.

20% of Type 2s are not overweight. 80% of obese people are not diabetic. Not a lot of people know that.

Jenny said...


I could not agree with you more. It was a bit of a shocker for me some years ago to test the family and discover that the hefty member I had always worried about had completely normal blood sugars and the thin, ultra-fit one did not.

Then I remembered that was the baby who was so thin the doctor was always calling me to check on how it was doing and the one who had the endless yeast infections.

Too bad they didn't know about inherited genetic diabetes back then.

Anonymous said...

Yes and your familial genes work completely different from mine.

Meanwhile in other families there are the typical strings of apple shaped people who die of cardiovascular disease which makes the pattern easier to spot.

In retrospect I think my father may have become a "typical" Type 2 in his later years as he put on a lot of midriff weight and became very sluggish and dropped off to sleep after eating. No genes that side of the family - BUT he was hyperthyroid when young and had most of the gland removed, so may well have become hypOthyroid later, which along with advanced age may have triggered it. He was never diagnosed though, and was still climbing mountains into his seventies so which came first, the inactivity or the weight gain, is hard to know.