The FastDay Forum

[carorees]

Ubizmo found an interesting website which summarises research on various diets. I found a fascinating article that describes how some people do well on high carb/low fat diets whereas others do well on low carb/high fat diets and that this difference may be due to differences in insulin sensitivity.
http://www.bodyrecomposition.com/fat-lo ... -loss.html
I wonder if investigating this further might help us to advise people who find they are not responding to the fast diet?

Discuss!

I think anyone who has several of the markers of metabolic syndrome has impaired insulin sensitivity. There is no doubt some percentage of overweight people who don't fall into this category, but I'd bet it's small.

I've followed Lyle's writings on and off over the years. He has finally concluded that "cyclic ketogenic" diet is the way to go. His main interest is bodybuilders, who need a lot of fuel, but it's interesting that 5:2 is itself a form of cyclic ketogenic dieting, for normal people.

[carorees]

Should people who don't find 5:2 is working look at their carb/fat balance as well as calories and experiment with high carb/low fat and then low carb/high fat to see if it makes a difference?

There is a subgroup of people on this forum who are finding weight loss very slow. I am keen to try to find some ideas that might help.

Should people who don't find 5:2 is working look at their carb/fat balance as well as calories and experiment with high carb/low fat and then low carb/high fat to see if it makes a difference?

There is a subgroup of people on this forum who are finding weight loss very slow. I am keen to try to find some ideas that might help.

I wish I knew the answer. I may well end up in that subgroup. The trouble is, the whole premise of 5:2 is that we can be ultra-vigilant and restrictive two days a week, and relaxed the other five. That's the trade-off that makes us willing to endure the hunger/deprivation. I think if people have to start counting carbs and fat grams on the "relaxed" days it's going to be too much to deal with.

But since I have nothing better to offer, I suppose it's worth a try. Maybe as a short-term tactic to break a stall...?

Very interesting Caroline & Ubizmo. But as I read the article, he is suggesting that insulin sensitivity and insulin secretion levels can affect compliance with the diet regime rather than affecting weight loss directly.

It seems a reasonable thing to try varying though, as it is outside the parameters of Dr M's fast diet.

My standard advice here to people struggling through the fast days has been 'cut down on the carbs', which works for me. But maybe for some, higher carbs (complex ones, presumably?) might help...

[carorees]

Maybe it's just the fast days that need adjusting not feed days...I lost weight very successfully (albeit temporarily) on Atkins and I tend to go low carb on fast days. Perhaps someone who had been very successful on low fat/high carb should go that way on fast days?

This is completely anecdotal but when younger I when through a stage of eatinga lot of carbs and veg with almost no protein except that found in dairy products. I was burning a lot of calories exercising everyday and lost a lot of weight at the time.

I find now that I can lose weight on a low carb diet but my body is not happy with it at all. I am best with a balance of carbs, veg and protein once a day. I attended a vegetarian school most of my life and wonder if that has anything to do with it as I would only eat protein in the evening at home (through no fault of the school, I was just a picky eater as a child).

There is a subgroup of people on this forum who are finding weight loss very slow. I am keen to try to find some ideas that might help.

Really appreciate that Carorees. I'm definitely going to cut carbs more, and have more fat on both feast and fast days, as I think that will help me shift weight, and further manage my hunger.

perhaps getting people to report blood sugar levels would be helpful - high glucose will imply high insulin. I noticed the Asda pharmacy was offering it for free, as do Lloyd's http://www.lloydspharmacy.com/en/info/f ... betes-test for people at risk.

Finally got to follow up the links on Lyle's page.

1. Pittas et al in "A Low-Glycemic Load Diet Facilitates Greater Weight Loss in Overweight Adults With High Insulin Secretion but Not in Overweight Adults With Low Insulin Secretion in the CALERIE Trial" compared two diets over 6 months.

The "High GL" diet was 60% carbs with an estimated daily average Glycemic Index (GI) of 86 (!) and a glycemic load (GL) of 116 g/1,000 kcal.

The "Low GL" version was 40% carbs with an estimated GI of 53 and GL of 45 g/1,000 kcals.

We can see that the low GL version is still a moderate carb diet, and that the GI of the high GL version is very high. Healthy women and men aged 24–42 years with a BMI of 25–29.9 kg/m2 and fasting plasma glucose <100 mg/dl were recruited.

Subjects were grouped according to their insulin value at 30 min (INS-30) after a 75-g oral glucose tolerance test. So we have four groups - high and low GL diets in each of high and low INS-30 insulin levels (above and below median value). All food was provided over 6 months and all groups lost weight with no significant differences in energy intake between groups.



The most statistically significant difference was between the weight loss of the Low Glycemic load diet between the two insulin groups - the high insulin level (high insulin response to glucose test) group lost more weight on the Low GL diet than the low INS-30 group.

A significant difference (at the 5% level) was also seen in the difference in response of the high INS-30 group to the two diets - they did better on Low GL.

The difference in response to the two diets among the low INS-30 group was not statistically significant, nor was the difference in performance of the High GL diet between the two insulin level groups.

In summary - if you have a good insulin response to glucose test then the evidence says you'll lose more weight on a Low GL diet. If you have a poor insulin response it may not matter, and on a High GL diet it doesn't matter what your insulin sensitivity is.

With N=8 subjects in each group and mixed gender the study is going to struggle to detect significance in modest differences, so the above outcomes should be taken in context. The usual call for further studies

Finally, the often used HOMA-R insulin sensitivity assessment did not find any statistical significant effects - "We also examined whether baseline HOMA-R predicted weight change, and we found no diet × HOMA-R interaction."

To be continued....

2. Cornier et al took a similar approach to compare obese women (23 to 53 yrs) with low insulin (<10) or high insulin (>15 microU/mL fasting) on two diets - 60% carbs/ 20% fat and 40% carbs / 40 % fat over 16 weeks with a daily deficit of 400 kcal.

The full paper describes the low insulin groups as "insulin sensitive" and the high insulin groups as "insulin resistant".

All groups lost weight and the less effective combinations lost about the 6kg predicted from the calorie deficit - the IR on the LF/HC and the IS on the LC/HF.

The more effective combinations of IR individuals on the LC/HF diet and the IS individuals on the HC/LF diet lost practically double the theoretical weight loss. No explanation was found for the difference and RMR measurements did not give statistically significant changes.



The difference in weight loss was statistically significant (p<0.01) for the choice of diet with the IS group and for the effect of insulin sensitivity on the LC/HF diet. A slightly lower level of significance (p<0.05) was found for the effect of diet choice in the IR group and the effect of insulin sensitivity on the HC/LF diet.

Insulin levels fell in both IR groups after 16 weeks, and in the High carb IS group.

Measured insulin sensitivity increased significantly in the IR group on LC diet, to the extent that their mean Si was the same as the two insulin sensitive groups after 16 weeks. This raises the question of what they should eat after the diet as they are no longer insulin resistant.

The "low carb" diet at 40% carbs would not be recognised as "Low Carb" by the Atkins or other Low Carb communities. The paper concludes :-

In conclusion, the state of Si determines the effectiveness of macronutrient composition of hypocaloric diets in obese women. Clearly, to lose weight, patients must be on a hypocaloric diet. To obtain maximal benefit, the macronutrient composition of a hypocaloric diet may need to be adjusted to fit the state of Si. IS individuals (those with fasting insulin levels below 10 μU/mL) should be recommended to consume an HC/LF hypocaloric diet (60% CHO and 20% fat). IR individuals (those with fasting insulinemia of above 15 μU/mL) should be recommended a diet containing 40% CHO and 40% fat (LC/HF). The short-term changes seen in this study have not been demonstrated to be durable over longer periods of time as seen in longer term studies lasting up to a year

[carorees]

It all seems to be adding up to something we can advise:

If you are eating high carb/low fat and not losing weight change to low(ish) carb/high fat. Conversely, if you are eating low carb/high fat and not losing weight, change to the reverse style. Using the mfp app/website will give an indication as to what the current balance is.

I suspect that most people who are chronically overweight (rather than just having put on a few lbs that they would like to shift) will be insulin resistant and will do better on a lower carb/higher fat diet. Such people may have spent years trying to follow health advice to eat low fat/high carb meals. Just ditching the diet foods (low fat yoghurt, dressings etc) might even be enough.

Anyone with type 2 diabetes will automatically be in the insulin resistant camp and so should go for a lower carb diet.

Comments?

Sorry as usual I am a bit slow to understand the jargon. Is 'high insulin secretion' (in Phil's post) a good thing or a bad i.e. is it associated with insulin resistance (bad?) or not? Or is it independent of it altogether?

[carorees]

High insulin secretion implies insulin resistance.

The more effective combinations of IR individuals on the LC/HF diet and the IS individuals on the HC/LF diet lost practically double the theoretical weight loss. No explanation was found for the difference and RMR measurements did not give statistically significant changes.

But what is really surprising is the suggestion that for those who are not insulin resistant, weight loss is more effective with a high carb diet.

And if there was no change in resting metabolic rate what mechanism can be proposed for these weight-loss differences? The only one I can think of is that the more effective regimes produced 'yo-yo' metabolisms with the bodies going into 'overdrive' and burning loads of extra calories before returning to the original RMR.

BTW Phil the image doesn't display - I tried the link in a browser and it says it is 'forbidden'...