Dr Joe

I want to address this issue of BCAAs and insulin spike at once here. Mainly because there’s a lot of language mis-appropriation which ultimately results in mis-information or should I say fake news on the relationship between insulin and BCAA supplements.

BCAAs and insulin have a funny relationship. Insulin is a responsive hormone to BCAAs. Meaning, BCAAs provoke an insulin response.

With that in mind, the question on your mind and indeed all BCAA users mind is probably this:
Do bcaas spike insulin? The short answer is; No, BCAAs don’t spike insulin. Surprised? You probably are because that’s not what you’ve been told. I shall explain this to you with the relevant science.

do bcaas spike insulin


Do BCAAs Spike Insulin?

Let me explain.

Yes, BCAAs and insulin do have a relationship.

And what would the nature of that relationship between insulin and branched-chain amino acids (BCAAs) be? That’s what this page is about.
Keep reading…

The truth of the matter is this. BCAAs do trigger the release of insulin. That much is true.

But here is the good news.

Yes, BCAAs do cause insulin secretion but it is NOT a spike. BCAAs do not spike insulin on their own when taken in isolation, contrary to what you may have been told elsewhere.

I will illustrate what actually happens when BCAAs are taken alone with 2 studies that looked into this issue shortly.

Keep reading…

I see weight loss and exercise enthusiasts worrying about this concept of an insulin spike all the time. Well, let me reassure you that bcaas do trigger insulin release but it is NOT an insulin spike.

I needed to repeat that to emphasize the point. A spike is a sudden rise of a biological marker (could be a hormone, enzyme, inflammatory substance) above the basal level and usually sustained for a variable length of time.

It could be a brief rise but the magnitude of the rise has to be significant to be considered a spike.

The rise has to get past a threshold for it to be clinically relevant. Any rise below that threshold is a considered a sub-clinical event.

A sub-clinical rise is not a spike. That is wrong use of the word, spike.

Let’ get Grammarly then, if we may.

The Oxford English Dictionary defines ‘Spike’ as:

A sharp increase in the magnitude or concentration of something

What happens with bcaas and insulin does not fulfil those criteria. Whether you examine the insulin secretion secondary to BCCA use from the clinical standpoint or from the Grammarly angle, the rise does not qualify to be referred to as a spike.

It is usually a small rise of insulin initiated by the bcaa supplement. Certainly not huge rise that is sustained.

Okay, let me illustrate my point further with the graph below. It’s from a study by Kalogeropoulo and his colleagues.

do bcaas spike insulin

To understand that graph, you have to know that leucine is the main amino acid in BCAA. Leucine is the most potent of the 3 amino acids in BCAA. BCAAs are made up of 3 amino acids – Leucine, Isoleucine and Valine.

Now if you noticed, I have been talking about BCAAs not causing an insulin spike, when taken alone in isolation.

If you take your BCAA with glucose from whatever source for example with a sports drink, then of course you will have an insulin spike as you can see on the graph.

The spike is more than the rise initiated by having a glucose drink in isolation.

The researchers concluded that a combination of BCAA and glucose has a synergistic effect. Meaning both leucine and glucose will help each other to cause a significant rise in insulin levels.

Now look at the insulin rise with leucine alone. It’s barely off the “ground”. In fact, it’s only slightly higher than water alone.

The insulin rise caused by leucine (a BCAA amino acid) and water is as flat as you will ever get. It’s a sub-optimal rise of insulin. It’s a marginal rise of insulin level caused by the BCAA leucine. Almost similar to the rise induced by water.

What you see there is certainly NOT a spike.

What About Valine & Isoleucine bcaa effect on insulin release?

If you are pedantic, you might say, well, that experiment was done with leucine alone but BCAA supplements have 2 more amino acids in the form of Valine and Isoleucine.

That may be true. But Valine and Isoleucine don’t play any role in protein synthesis and indeed both do not have any influence on insulin release when you take BCAAs.

Valine’s role is to enable you fight exercise fatigue. Valine competes with the amino acid called tryptophan in the brain.

Tryptophan is a useful ingredient in the synthesis of 5-Hydroxytryptamine (5-HT) otherwise called serotonin. If less tryptophan is available, less serotonin is made. Serotonin is to blame for your exercise fatigue.

Valine by competing with tryptophan reduces the production of excess 5-hydroxytyptamine (5-HT). Low 5-HT (serotonin) means you don’t fatigue out quickly. You exercise more. More volume.

That’s the role of valine.

What about isoleucine?

Isoleucine is also a supporter of leucine. Its main role is activating PPAR receptors. When activated, these receptors promote fat burning. To make its role count even more, isoleucine also discourages fat storage.

That’s the role of isoleucine.

Both isoleucine and valine do not have any effect on insulin secretion and insulin levels. So, their exclusion from that study makes no difference to what happens inside our body when we take BCAAs.

If you are looking for further evidence, you can have a look at this other study that used BCAA in young men participants.

In that study, the peak insulin rise was 8.5 microunits/ml of insulin which is very similar to the previous study I alluded to earlier.

The peak insulin rise occurred at around 15 minutes also similar to the other study.

That insulin rise was described by the authors of the second study as modest. Indeed, that’s about the only way to describe 8.5 microunits/ml rise of insulin.

It certainly cannot be described as a spike.

The findings from those 2 studies should have made it clear to you by now that; BCAAs do not cause a spike of insulin but a gentle marginal rise.

I just hope the gurus will stop using the word ‘spike’ when referring to the relationship between BCAAs and insulin.

When your fitness guru uses the phrase “BCAA insulin spike”, as a follower, your mind visualises something more dramatic than you saw on that graph.

That’s not the case and it has been tested in other studies. Those are just two studies I pointed out to clarify the situation.

bcaas and insulin levels

BCAA intermittent fasting implications

Does the insulin rise have any fasting implications?
Not if you put things into perspective.

Remember intermittent fasting has a lot of benefits and yes, having BCAAs may mean you are technically breaking your fast but only by a very small margin.

It’s a small insulin rise. One of the ways intermittent fasting works to promote fat burning is the fact that fasting keeps insulin levels low. Really low.

Low insulin level enables your body to access your body fat stores to be used as energy source.

Even though leucine in the BCAA may trigger insulin rise as you saw in the graph above, the level of rise is too small to have a negative effect on fat burning.

These things are dose-dependent. The 10 gm of BCAA which is about the maximum dose of BCAA I recommend you take is not going to provoke a significant insulin rise to sabotage your intermittent fasting goals.

It’s NOT a spike!

You will still burn fat regardless.

To attain a spike in insulin, your dose of BCAA will probably be in the range of 70 gm taken at the same time as a single dose. Not recommended.

If you still have doubts, do the following:

==> Reduce the dose of the BCAA to half the recommended dose.

Take 5 gm of BCAA instead of 10 gm. There. That should certainly fix your fears and concerns about any BCAA-induced insulin rise.

Of course, by reducing the dose you are correspondingly reducing the beneficial impact of the BCAA.

In fact, this same study done with 5 gm of BCAA actually confirms that the insulin rise you experience with 5 gm of BCAA is just a temporary elevation. 5 gm of BCAA is a manageable dose that will guarantee metabolic stability.

In any case, whatever insulin response you experience from taking BCAA supplements, it’s a mono-phasic response. This is in sharp contrast to what happens when you have a meal.

A regular meal will usually provoke a second-wave insulin response to peg blood sugars down unless you are very insulin-sensitive. Not so with BCAAs. No metabolic disruption at this dose.

==> Do not take your BCAA supplement with any sugary product

As you saw in the preceding chart, taking a combination of BCAA and glucose, is guaranteed to give you an insulin spike.

Never combine the two, unless you desire an insulin spike of course. Sugary products will include sports drink, smoothies, energy bars etc.

==> Take your BCAA close to when you are about to end your fast

I usually advice taking your BCAA supplement in the last hour of your intermittent fasting.

This certainly takes care of any concerns you have because your fast is coming to an end shortly anyway, so any insulin rise will no longer matter.

You are bringing your “end of fast” (if you like) forward by an hour. So what? It matters not. You can’t be too pedantic about these things, otherwise you miss out on proven benefits.

==> Take your BCAA supplement about 30 minutes before your workout

Doing so ensures you are feeding your muscles directly before your workout.

BCAAs are protective of muscle. BCAA are usually spared of the journey through the liver. Normally protein from your regular food goes through the liver after digestion. After digestion the absorbed amino acids from the proteins get redistributed from the liver to peripheral sites like your muscles.

Amino acids from BCAA however by-pass the liver and head straight to your muscles. In the muscle, BCAAs promote synthesis of proteins through the mTOR pathway and reduce breakdown of protein.

You get the muscle protection benefits whilst seizing the anabolic effects of the available insulin in circulation. A win-win situation.

To put things in perspective, use the following regime. Of course, you can change the hours of the day to suit you.

11:30 – 12 Noon Take your 10 gm of BCAA (or 5 gm, if you prefer) supplement
12 Noon – 1 pm Training hour
1 pm – Have your After-workout meal
4 pm – 2nd meal of the day (Optional meal. You can just eat twice)
8 pm – Have your last meal of the day. Start your intermittent fasting again.

If you use this regime, you can exploit the little rise in insulin from using BCAA supplement. Remember, it’s not a spike.

Suggested further reading:
3 HAPPY HOUR Fat Burning Strategies