Understanding your metabolism to create an effective nutrition plan

Thursday, March 22, 2018. Author Alex Auld

Alex Auld Blog Series

This blog series highlights and discusses the individual results of FitnessGenes Partnership Program manager and multi-event endurance athlete, Alex Auld.

Now that we’ve established how DNA regulates protein production, we can look at which proteins are produced by which genes, and the impact they have on exercise, nutrition and physiology.

First up is UCP2, a gene that influences metabolic efficiency.

UCP2: A gene for metabolism

You will often hear metabolic rate being referred to as being ‘fast’ or ‘slow’, with people who are looking to lose weight wishing they had a ‘faster metabolism’.

At FitnessGenes, we instead refer to metabolism as being ‘efficient’ or ‘inefficient’, depending on how successfully you convert calories you consume into energy for movement and growth. 

What is commonly known as a ‘fast’ metabolism is actually inefficient, because an increased percentage of the calories consumed are lost as heat rather than converted into energy. This occurs through a process called ‘uncoupling’.

Uncoupling proteins

Uncoupling is carried out by the uncoupling proteins, which in part are encoded by the UCP2 gene. 

A greater presence of uncoupling proteins results in uncoupling occurring at an increased rate, leading to a greater loss of the chemical energy in your food as heat (or thermal energy).

On the other hand, if levels of the uncoupling proteins are low, the rate of uncoupling is reduced, and a greater proportion of the calories in your food are converted into energy for use by cells.

The three variations of UCP2 (AA, AV & VV) give rise to varying levels of uncoupling proteins. Therefore, by knowing your UCP2 variation, we can determine your metabolic efficiency and make recommendations to help you manage this.  

My result: AV

The two alleles (or genetic variants) or UCP2 are:

  • A = Fast/inefficient metaboliser
  • V = Slow/efficient metaboliser

I carry a copy of each allele, which means that I am likely to produce intermediate levels of uncoupling proteins and have an intermediate metabolic efficiency compared to AA and VV carriers.

This is an important insight when calculating my total calorie intake, as I won’t have to adjust beyond what is recommended for my body composition, activity level and goal to allow for any increased or decreased uncoupling protein activity.

50% of Europeans share my AV variation, and it is even more commonly found in African populations (60%). 

Other UCP2 variations: AA and VV


If you carry two copies of the A allele, this classifies you as a fast metaboliser due to increased uncoupling protein activity. Compared to AV and VV, a higher percentage of the calories you consume are lost as heat rather than converted to energy.

While this may appear beneficial for someone who is looking to lose weight, it becomes problematic for those who want to build muscle or compete in endurance events, where calories must be utilised very efficiently. Therefore, in order to maximise results and performance in these disciplines, AA carriers need to account for their increased uncoupling activity when calculating their total calorie intake.


In contrast, carriers of two copies of the V allele are most efficient in converting consumed calories into energy. It is therefore unsurprising that research has consistently associated this allele with top-class endurance athletes.

However, for those who are not top-class athletes, the VV variation does magnify their risk of weight gain if their calorie intake is higher than their calorie expenditure.


Which variation do you carry?

So next time you hear someone talking about metabolic rate, remember it’s not how fast or slow you digest food, but, rather, how efficiently you are converting that food into energy to use!

Want to know for sure whether you have an efficient or inefficient metabolism? UCP2 is just one of the 41 genes we analyse at FitnessGenes. Click here to purchase your personal DNA analysis or Genetic Workout System.

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