Carbs, fat and breakfast

[MikeS]

Doesn't some of this originate with that carb-backloading guy?

It's pretty well known that high-gi carbs do release more insulin which does increase the availability of tryptophan in the brain which in turn increases substrate saturation for the enzyme tryptophan hydroxylase and thus, more serotonin which yes can cause you to feel sleep but also to feel happy etc.

I think Ben is over-simplifying things far too much and has experienced a placebo effect when it comes to him feeling lethargy even after oat consumption.

Reason I say that is because the above depends on insulin. More insulin = more tryptophan hydroxylase saturated = more serotonin.

The interesting thing about this is protein + fat and have a negative effect on this. So more fat/protein = less tryptophan hydroxylase saturation = less serotonin.

So then the obvious thing to ask is "well if protein & fat reduce serotonin in the brain {via the above mechanism}, then what would a mixed meal do?" and that would be a good question since only stupid people wake up and eat waffles laden with syrup and ice cream for breakfast.

Thankfully one study group published a paper in the british journal of nutrition looking at the effects of mixed meals of differing glycemic /loads/indexes on the tryptophan:neutral amino acid ratio.

As it turns out the higher GI and GL meal with the least protein/fat (this meal had 175g carbs) in lead to the greatest increase - about a 23% increase from baseline - in tryptophan and thus potentially serotonin, which we'd expect.

Interestingly the mixed meal (some proteins/fats/carbs) that was high GI (again 75g carbs, 18g protein, 8g fat) still lead to an increase of 15% above baseline.

The mixed meal that was lower GI (again 75g carbs, 18g protein, 8g fat) lead to only an 8% increase from baseline.

So what does this all mean?

Basically that total amount of carbs eaten matters (more carbs > more insulin > more trytophan availability etc) but also GI/GL. Higher GI/GL meals can still increase serotonin even in mixed meal situations but lower GI/GL meals (such as oats) may not increase tryptophan to any significant degree in a mixed meal situation.

Baring in mind that in this study they only ate 8g fat and 18g protein. Most of us here when having oats for breakfast are likely to be consuming a macro make up more to the tune of 30-50g protein, 10-20g fats and the rest carbs.

So whilst Ben is right that higher carb = serotonin = propensity for sleepiness, unless his receptors are particularly sensitive to serotonin, or his body is particularly sensitive to carb intake, having oats wont be making him sleepy any time soon. Unless he has experienced the famous placebo effect of course (diet guru convinces him carbs in the AM are bad, Ben seems to experience bad stuff when he eats carbs in the AM, not because that's what they do but because that's what he's expecting.)

Overall if you can consume carbs without much rise in insulin, you'll avoid the effect of increasing serotonin production in the brain.

Not I'm not stating here that you should or shouldn't eat carbs in the AM, just that it isn't as clear cut as Ben seems to think.

Hope all that makes sense.

References for the geeks out there:

British Journal of Nutrition: http://www.ncbi.nlm.nih.gov/pubmed/21349213

High carb increases but high protein decreases serotonin: http://ajcn.nutrition.org/content/77/1/128.full.pdf

[lksurf2]

Doesn't some of this originate with that carb-backloading guy?

It's pretty well known that high-gi carbs do release more insulin which does increase the availability of tryptophan in the brain which in turn increases substrate saturation for the enzyme tryptophan hydroxylase and thus, more serotonin which yes can cause you to feel sleep but also to feel happy etc.

I think Ben is over-simplifying things far too much and has experienced a placebo effect when it comes to him feeling lethargy even after oat consumption.

Reason I say that is because the above depends on insulin. More insulin = more tryptophan hydroxylase saturated = more serotonin.

The interesting thing about this is protein + fat and have a negative effect on this. So more fat/protein = less tryptophan hydroxylase saturation = less serotonin.

So then the obvious thing to ask is "well if protein & fat reduce serotonin in the brain {via the above mechanism}, then what would a mixed meal do?" and that would be a good question since only stupid people wake up and eat waffles laden with syrup and ice cream for breakfast.

Thankfully one study group published a paper in the british journal of nutrition looking at the effects of mixed meals of differing glycemic /loads/indexes on the tryptophan:neutral amino acid ratio.

As it turns out the higher GI and GL meal with the least protein/fat (this meal had 175g carbs) in lead to the greatest increase - about a 23% increase from baseline - in tryptophan and thus potentially serotonin, which we'd expect.

Interestingly the mixed meal (some proteins/fats/carbs) that was high GI (again 75g carbs, 18g protein, 8g fat) still lead to an increase of 15% above baseline.

The mixed meal that was lower GI (again 75g carbs, 18g protein, 8g fat) lead to only an 8% increase from baseline.

So what does this all mean?

Basically that total amount of carbs eaten matters (more carbs > more insulin > more trytophan availability etc) but also GI/GL. Higher GI/GL meals can still increase serotonin even in mixed meal situations but lower GI/GL meals (such as oats) may not increase tryptophan to any significant degree in a mixed meal situation.

Baring in mind that in this study they only ate 8g fat and 18g protein. Most of us here when having oats for breakfast are likely to be consuming a macro make up more to the tune of 30-50g protein, 10-20g fats and the rest carbs.

So whilst Ben is right that higher carb = serotonin = propensity for sleepiness, unless his receptors are particularly sensitive to serotonin, or his body is particularly sensitive to carb intake, having oats wont be making him sleepy any time soon. Unless he has experienced the famous placebo effect of course (diet guru convinces him carbs in the AM are bad, Ben seems to experience bad stuff when he eats carbs in the AM, not because that's what they do but because that's what he's expecting.)

Overall if you can consume carbs without much rise in insulin, you'll avoid the effect of increasing serotonin production in the brain.

Not I'm not stating here that you should or shouldn't eat carbs in the AM, just that it isn't as clear cut as Ben seems to think.

Hope all that makes sense.

References for the geeks out there:

British Journal of Nutrition: http://www.ncbi.nlm.nih.gov/pubmed/21349213

High carb increases but high protein decreases serotonin: http://ajcn.nutrition.org/content/77/1/128.full.pdf

And you thought rx was going stale

Lol kidding bro I really like all the info you shared!