Low carb diet and insulin resistance

[CosmicFish]

I've been considering a very-low carb diet for my next cut (some way off still). Given that, the majority of the calories will likely end up coming from fat. I've recently heard that high fat diets can make you insulin resistant - odd, since I'd have expected the opposite. Basically I'm wondering:

1) if there's guidelines for a maximum amount of time to follow a high fat diet before insulin resistance starts to kick in.

2) if there is a rough guide for the maximum amount of fat you should be consuming before it becomes unhealthy?

[NU_nutrition_TS]

Forget it. That's just RB quoting 'rat studies'.

Quote

Recent studies in healthy subjects
Only in the past several years have detailed studies regarding LCD metabolism been performed (Table 2Go). In a metabolic ward study, 8 healthy volunteers were provided a 2-d eucaloric (weight-maintaining) diet in which 60% of energy was from carbohydrate and 30% of energy was from fat; this diet was followed by a 7-d eucaloric diet in which 5% of energy was from carbohydrate and 60% of energy was from fat. Both diets were consumed while the subjects maintained their typical sedentary lifestyle (14). With the 5% carbohydrate diet, serum glucose initially declined but then returned to baseline after a few days. Whereas fasting insulin did not differ between the 2 diets, the 24-h area under the curve (AUC) for insulin was >50% lower with the 5% carbohydrate diet than with the 60% carbohydrate diet. After 1–2 d of the 5% carbohydrate diet and persisting through the 7-d period, serum ß-hydroxybutyrate increased from 0.1 to 0.4 mmol/L and free fatty acids increased from 0.2 to 0.4 mmol/L. In addition, muscle glycogen (measured by muscle biopsy) was reduced by 20% after 9 d.

Quote

Glucose kinetics were assessed by stable-isotope techniques while resting metabolic rates were calculated from oxygen consumption (VO2) and carbon dioxide production (VCO2) was measured by using a metabolic cart. By day 2 of the 5% carbohydrate diet, both the glucose rate of appearance and rate of disappearance decreased by 20%, and they remained suppressed on day 7. In addition, postabsorptive carbohydrate oxidation decreased progressively over the 7-d duration, and this decline was greater than the decline in glucose uptake. This means that the rate of nonoxidative glucose disposal (ie, carbohydrate storage) increased in the postabsorptive state with the 5% carbohydrate diet. These changes suggest that there is a shift from the use of glucose to the use of ketones and free fatty acids as metabolic fuels, and that glycogen formation increases from baseline.

Quote

Another set of studies was performed to evaluate the metabolic effects of diets consisting of 0–2% carbohydrate, 11–15% protein, and 83–88% fat in healthy volunteers (15-19). (These experimental diets contained a higher percentage of fat than is typically observed in an ad libitum LCD, and thus they were more characteristic of an ancestral Inuit diet or the ketogenic diet for epilepsy.) Nonetheless, these studies elucidate many metabolic aspects of carbohydrate restriction. Serum glucose, insulin, and C-peptide concentrations with the 2% carbohydrate diet were lower than those with the 85% carbohydrate control diet. After 11 d of the 2% carbohydrate diet, gluconeogenesis was 15% higher and glycogenolysis was 55% lower than that after 11 d of the 85% carbohydrate diet (15). In a related study by the same group, weight-maintaining diets containing either 89% carbohydrate, 11% protein, and 0% fat or 0% carbohydrate, 11% protein, and 89% fat were compared over a 15-d period (18). In that study, gluconeogenic rates did not differ significantly between the diets. When a hyperinsulinemic euglycemic clamp technique (200 pmol/L) was used, insulin-mediated suppression of glucose production and stimulation of glucose disposal did not differ significantly between the diets.

Low-carbohydrate nutrition and metabolism, Eric C Westman, Richard D Feinman, John C Mavropoulos, Mary C Vernon, Jeff S Volek, James A Wortman, William S Yancy and Stephen D Phinney, American Journal of Clinical Nutrition, Vol. 86, No. 2, 276-284, August 2007.

Also, low carb/high fat diets are renown for lowering triglycerides and increasing HDL-C; the ratio between these two are a good indication of insulin sensitivity (the lower the better).

[Ripped Barbarian]

Insulin resistance is a 'natural' part of a high fat diet.

If your body does not have an influx of glucose or glucose precursors (protein) then it has to become insulin resistant to maintain glucose homeostasis and muscular energy supplies (which become predominantly fatty acids)

Rat studies show it but humans have too, people coming off high fat diets have often had bad OGTT results, or at least Hyperinsulinemia....it does improve after returning to a higher carb diet but it's something to be taken into account.

Like i say, if you stick to low carbs, high fat for your life no problem, if you swap between the two you are going to screw yourself up. (or have a high fat, high insulin dependant diet....like western society)
What is even more important is cellular insulin sensitivity through cell membrane fluidity etc, i.e not conusming trans fats/vegetables oils or being in a state of chronic oxidative stress/inflammation.

Low carb/high fat benefits certainly have benefits in the short term but the body will adapt and you put yourself in a state of not being able to handle influx of blood glucose/insulin (from carbs or protein) for athletes this is not ideal.
Short term any studies will see that insulin is lowered a low carb diet....it's pretty simple stuff really.
People think it's a 'cure' for insulin resistance (cell membrane disfunction) but it's not, it's simply reducing insulin load for a given insulin sensitivity.

It's like driving a car gently that has a problem with high RPM's...you won't notice it so you think it's cured.

[hailtotheking]

From what ive read it seems RB is correct, although the effect is transient.
RB's theory sounds plausible, although Mauro DiPasquale suggests in his Radical Diet book:

Quote

It’s important to know that insulin resistance, because of its complexity, can actually be a good thing in certain conditions, and can be used to maximize body composition. That’s because insulin resistance can be manipulated so that it applies differently to different body tissues and metabolic processes.
Insulin resistance in glucose metabolism [as occuring with low carb diets], which can allow increased use of free fatty acids, and therefore body fat, as fuel, can be present along side of insulin sensitivity in amino acid transport and protein synthesis, which maximizes muscle mass, and with insulin resistance to fat tissue, which increases lipolysis and decreases lipogenesis.
The end result of the variation in insulin resistance and insulin sensitivity in different tissues makes it easier to lose weight, especially body fat, and to maintain muscle mass.

[Ripped Barbarian]

[QUOTE=hailtotheking;352480]From what ive read it seems RB is correct, although the effect is transient.
QUOTE]

its actually called. 'Transient insulin resistance.' medically.

This is why studies show a 'high fat diet' (with a few carbs or high protein included) is bad.
You're body dosn't quite know which fuel to use predominantly.
This is why you see contradictory studies of the benefits of low fat diets and high fat diets.
How could a low fat diet and a high fat diet both be good?

It differs from 'permanent' insulin resistance thankfully, caused by a breakdown in cellular fluidity. (don't eat veg oil, trans fats or other crap and you'll be alright, lack of exercise too...things like AMP acivated kinase really switch on GLUT4)

the metabolic switching point seems to be around 38% fat in a diet from all the studies i have seen.

so, go 25-30% fat with carbs and protein or go all out on the fats with no carbs.

[CosmicFish]

Cheers for the feedback chaps, even though about half of that went over my head.

Quote

If your body does not have an influx of glucose or glucose precursors (protein) then it has to become insulin resistant to maintain glucose homeostasis and muscular energy supplies (which become predominantly fatty acids)

I guess it would be naive of me to assume that getting a load of protein with the fat would stop this happening?

Quote

the metabolic switching point seems to be around 38% fat in a diet from all the studies i have seen.

Interesting. Is that by weight of food or by calories? I ask because, according to fitday, my current macro breakdown by calories is 22/20/57 Prot/Carb/Fat. I don't specifically try to restrict carbs or go for fats, I just eat a diet of mostly meat, fish, fruit, veg, cheese, eggs, milk & nuts. Being well over 38% fat by calories, this would seem to suggest that I might be insulin resistant already?

[NU_nutrition_TS]

I go with Mauro DiPasquale on this one: So what? It's beneficial. As the studies I quoted show; the area under the curve for insulin on the low carb diet is greater then 50% less for the low carb diet than for the high carb diet. That means less overall insulin exposure - got to be good for health and insulin sensitivity.

[Ripped Barbarian]

Quote

I go with Mauro DiPasquale on this one: So what? It's beneficial. As the studies I quoted show; the area under the curve for insulin on the low carb diet is greater then 50% less for the low carb diet than for the high carb diet. That means less overall insulin exposure - got to be good for health and insulin sensitivity.

Short term or long term in that study tho?

My point is, that long term insulin levels might not be less.
someone going on a low carb diet from a high carb diet will certainly have lower insulin levels, in fact as low as they can possibly be for the first few days.

I think being insulin sensitive + eating a low GI carb/high protein diet will produce the lowest overall insulin levels.

Sort of keeping in the 'sweet spot' if you like.
Anyway it'd be interesting to see more studies in this area.

I personally found my insulin sensitivity dramatically dropping on a high fat diet and my insulin levels rising, mabye some people have it better than me, some don't get the stress levels i did on a high fat diet.

I found that high stress levels on high fat diet = increase blood glucose with decreased insulin sensitivity = hyperinsulanemia.

I lost most of my hair during my high fat diet, since going to low gi carbs + protein again it's actually grown back a little bit.
Insulin resistance is associated with MP baldness because insulin has effects on the alpha 5 reductase IIRC.

[NU_nutrition_TS]

Quote

Short term or long term in that study tho?

15 days. If the was a way to measure insulin myself - inexpensively - I'd ruddy well be willing to have OGTT just to put this to bed once and for all - I've been on a low carb diet for years!

[Ripped Barbarian]

Quote

15 days. If the was a way to measure insulin myself - inexpensively - I'd ruddy well be willing to have OGTT just to put this to bed once and for all - I've been on a low carb diet for years!

Fair enough, did you not get some more strips for a OGTT test. (not that i think a OGTT is always that accurate for insulin sensitivity/insulin levels, especially whilst on a low carb diet but i guess the area under the curve and shape can give some indication)

The thing that twigged me the other day was you said you had acne appear.

It's not acutally commonly related to testosterone levels but insulin is a much more common cause.
When i have other symptoms of hyperinsulinanemia i also get the acne...

Your insulin levels probably arn't that high (but possibly equal to someone enjoying a 'normal' diet) but when you introduced higher protein and a few carbs your body reacted with bad triglyceride/HDL ratio, indicative of poor insulin sensitivity and hyperinsulinanemia.