Fixed Protein + Dynamic Carbs, Fats, and Calories

Rehwyn

TL;DR - I'd like to request the ability to set a fixed goal for one macronutrient (in this case protein) and dynamic goals for others (such as carbs, fats, and calories). Alternatively, I'd like the ability to set fixed "base" macronutrient targets based on no activity, but dynamically update macro targets based on logged exercise/activity using a different ratio than the "base" macro targets (for example 0:75:25 for additional protein:carbs:fats based on exercise). Perhaps this can already be done, but I have not yet found out how, if so.

Longer version -

There's a good bit of emerging research that indicates that an improved protein model is that all athletes (no matter your height, weight, or sex) should aim for about 120 grams of protein daily, divided as evenly as possible into 20 gram servings that are themselves separated by around three hours.

Realistically, having 6 meals per day with exactly 20g of protein is a bit overkill for my needs. With this in mind, in a different tracking app, I have set up my macro targets such that I am for 5 "meals" per day of 20-30g protein and a daily total of 120g protein. My "base" macronutrient goals (including calories, carbs, and fats in addition to protein) are manually fixed in the other tracking app based on no activity, and any additional calories from exercise and activity dynamically update calories to meet my net calorie goal and dynamically add additional carbs and fats at a 75:25 ratio to meet that calorie goal.

At present in Cronometer, it seems that macronutrient targets have to be either all fixed or all dynamic and there does not seem to be a way to have activity and exercise dynamically change goals for only some of the macronutrient targets.

Thanks!

Hilary

Thanks for the suggestion, and well thought out examples of how you would use this. This is exactly the kind of constructive user feedback that helps us develop and improve features in our software.
We are hoping to improve the functionality of setting targets in the near future, so I have passed on your feedback to the team! - Thanks!

Martelli

This feature would be an athlete's dream.

As an athlete, when I log exercise activity, I want my macro targets to dynamically update (for example 0:25:75 for additional protein:carbs:fats) so that I can optimize my nutrition and recovery.

In addition to dynamically updating my macros, I would like to dynamically update Nutrient Targets as well (for example, the Lipid Nutrient Target, Polyunsaturated (PUFA)).

p0wer_lifter

@Rehwyn, do you have any sources for the studies you mention?

It seems remarkable to me that a 6’3” 220 pound male wrestler should have the same amount of protein as a 5’2” 110 pound female marathon runner.

That said, I am probably coming from an outdated perspective, so would be very interested to see some new research on this.

Rehwyn

@p0wer_lifter Sure, I can provide a few. Note that I'm not an expert, and I originally found all this info researching rock climbing nutrition, though it seems pretty widely applicable.

https://pubmed.ncbi.nlm.nih.gov/11706282/

This study found that when controlling for amount of protein and type of stimulus, there was little or no difference in physiological response to protein between different genders.

https://pubmed.ncbi.nlm.nih.gov/24257722/
https://pubmed.ncbi.nlm.nih.gov/19056590/
https://pubmed.ncbi.nlm.nih.gov/19699838/

These found optimal muscle protein synthesis rates at 20-30g of high-quality protein per meal, with no significant increases at 40g or 90g. This was consistent across different genders, muscle mass, etc.

https://pubmed.ncbi.nlm.nih.gov/23459753/

This study compared different timings of consuming 80g of protein over 12 hours, and found 3 hour intervals to be more optimal than 1.5 hours or 6 hours. Worth noting it was only trained males and whey protein, however, so more study would be helpful.

https://pubmed.ncbi.nlm.nih.gov/16507602/

There's also this evidence that elderly individuals may need more leucine (and therefore more protein) for optimal stimulation.

Also worth noting this is only looking at the effect of protein on muscle protein synthesis, and not other body functions.

Given the above, it seems that a good recommendation is 25-35g of protein per meal, with 3-6 meals per day separated by 3+ hours.

p0wer_lifter

Thank you for this. I don’t see any mention of body weight within the subject population, nor results related to body weight. Did I miss it?

I do see that one study gave various amounts of protein based on body mass, but nothing indicating what, if any, body mass difference there was between subjects.

mwglow15

I'd like to second this feature request!

As an endurance athlete the generally accepted method is to replace most of your exercise calories with carbs while keeping fats and proteins relatively consistent. This way you aren't eating 400g of protein on days that you bike for 5 hours. I could now just use fixed values and then just go over target on carbs till I reach my daily calorie burn but it would be great to be able to assign custom macro breakdowns for calories burned through certain exercises. (i.e. maybe 50/50 carb:protein for weightlifting calories but 85/15 for calories burned during aerobic sports.

Thanks!

AnonJohn

To a degree you can do this with the keto mode. You can specify protein (if indirectly, as proportional to lean body mass) and grams of carbohydrates. But it ends up not scaling well with the "athletic bonus". At 1g carbs / 50 kcal of exercise, it is very low relative to energy expenditure. Letting users specify their own athletic bonus would be a quick way to provide this kind of dynamic macro calculation.

None of this has anything to do with keto, so that's kludge. But cronometer is already most of the way there ...

There have been a variety of requests for this functionality. i.e.

https://forums.cronometer.com/discussion/4925/add-a-dynamic-macro-ratio-option-where-protein-and-fixed-and-exercise-add-carbs

https://www.reddit.com/r/cronometer/comments/naaiux/set_protein_to_a_fixed_target_and_dynamic_for/