Fixed Protein and Fat, Flexible Carbs
To keep protein and fat fixed while exercise adds only carbs, separate your base macro targets from the way you allocate extra activity calories. Set the activity split to 0% protein, 100% carbs and 0% fat. PlateLens makes that split configurable, so a training day can raise your carbohydrate target without raising the other two.
One base plan, a separate activity bonus
A long ride should not automatically change a protein target you deliberately chose. The same applies to a fixed fat target. The question is where the additional activity energy should go: all to carbohydrates, across several macros, or only into the calorie total.
In PlateLens, your saved base goals and the activity allocation are separate settings. Choose your daily protein, carbohydrate and fat goals first. Then choose how the recorded activity bonus changes the effective targets shown during the day. This works with device activity and exercise you enter manually.
Example: 400 activity calories, 100 g more carbs
Here is an illustrative base plan of 2,200 kcal with a 100% carbohydrate activity allocation. These numbers demonstrate the calculation; they are not a suggested diet.
| Target | Saved base | Activity bonus | For this day |
|---|---|---|---|
| Calories | 2,200 kcal | 400 kcal | 2,600 kcal |
| Protein | 140 g | 0 g | 140 g |
| Carbs | 275 g | 100 g | 375 g |
| Fat | 60 g | 0 g | 60 g |
If your logged meals contain 270 g of carbohydrates, the difference from the new target is 105 g. Your protein and fat goals are still 140 g and 60 g. The app recalculates the target as recorded activity changes; the amount you have eaten comes from your meal log.
The bonus uses active energy, which can include ordinary movement as well as a workout. It is a configurable way to account for recorded calories, not a measurement of carbohydrate use or a forecast of tomorrow’s training.
Choose 100% carbs or your own percentages
Open More → Nutrition & Goals → Activity calories. Turn on Add activity to my targets, choose Custom percentages and use Put 100% into carbs, or enter your own split. Press Save to apply all three percentages together. The web app has the same allocation controls in its nutrition targets settings.
The percentages refer to the extra energy. For each macro, bonus grams equal activity kcal × its percentage ÷ 100 ÷ kcal per gram. Protein and carbohydrate use 4 kcal/g; fat uses 9 kcal/g. A 20% protein, 70% carbohydrate and 10% fat split of 400 kcal adds 20 g protein, 70 g carbs and about 4 g fat after rounding. Whole-gram targets can introduce a small rounding difference.
Set any macro to 0% to hold it at its base target. Choose Calories only to keep all three macro targets fixed, or Carbs and fat to use the energy proportions of your base carbohydrate and fat goals. Turning the main switch off suspends the whole activity adjustment and preserves your saved allocation.
Check the starting budget when using adaptive expenditure
Adaptive expenditure learns from your recorded intake and weight trend and already reflects your usual activity. Adding a separate activity bonus can overlap with that estimate. PlateLens warns when you enable the combination. Choosing a percentage split changes the allocation of the bonus; it does not change the learned expenditure itself.
A runner or cyclist following a plan with fixed protein and fat may prefer the carbohydrate-only option. Someone whose plan already covers their typical training may prefer to leave the activity addition off. The useful choice depends on what your base plan already includes, rather than on having more settings enabled.
Today, earlier workouts and reports
Today’s targets update as activity is recorded or synchronized. A new allocation applies from today. Logging a missed exercise for an earlier date changes that date using its own recorded settings. Older days without a captured configuration can carry reconstructed targets, which are identified where available.
Daily details distinguish the base target, activity adjustment and effective target. PDF nutrition reports show those values for the reported period and compare intake with the relevant targets, including periods that contain more than one allocation. The Apple Watch companion shows daily nutrition progress; configure the allocation on the phone or web.
See the activity-adjusted targets guide for the controls, historical behavior and troubleshooting.
What to check when comparing macro trackers
Look for controls for the exercise bonus, as well as controls for your base macros. MyFitnessPal documents exercise-calorie redistribution for Premium members. Cronometer documents ratios that change with the energy target and fixed gram targets. Those are different concepts: verify the exact combination you need.
PlateLens combines fixed base targets with a separate percentage allocation for activity. That is the setting to look for when the requirement is “keep these two macros fixed and let only the third change.”
Frequently asked questions
Which app keeps protein and fat fixed while exercise adds carbs?
PlateLens lets you save your base protein and fat targets in grams and send 100% of extra activity calories to carbohydrates. Open Activity calories, enable the adjustment, choose Custom percentages and select Put 100% into carbs. Synced activity and manually logged exercise then update the daily carbohydrate target while your saved protein and fat targets stay fixed.
Can I choose a different split for exercise calories?
Yes. PlateLens accepts whole percentages for protein, carbs and fat that total 100%. These percentages apply only to the extra activity energy, not your entire daily calorie target. A 0% share leaves that macro at its base target. You can also choose Calories only or split the bonus between carbs and fat in your base proportions.
How many extra carbs do 400 activity calories add?
With 100% of the activity bonus assigned to carbs, 400 kcal adds 100 g of carbohydrates. A base target of 275 g becomes 375 g. If you have logged 270 g so far, 105 g remains against that target. Protein and fat remain at their base values. This is the chosen accounting rule, not a measurement of how much carbohydrate your workout used.
What happens on rest days or when I switch the setting off?
Each day uses its own recorded activity. A rest day can still include walking or other active energy; with no activity calories, there is no bonus. Turning the adjustment off removes its effect on calorie and macro targets and retains the saved distribution. Turning it back on restores that distribution from today without rewriting earlier days.
Does changing my split recalculate yesterday?
Changing the split applies from today. Earlier days retain their recorded settings. If you later add, edit or delete an exercise on an earlier date, that date is recalculated using its own settings. Older records without a captured configuration may show reconstructed targets. Reports use the settings and target data available for the period, rather than applying today’s split to every past day.
Can I combine activity calories with adaptive expenditure?
You can, but adaptive expenditure already reflects your usual activity. Adding activity calories on top may count part of it twice. PlateLens shows a confirmation when enabling the combination. Change the activity distribution only if the extra energy should be added to your targets; the split itself does not change the learned expenditure estimate.
Will calories from Suunto, TrainingPeaks or Intervals.icu work?
PlateLens reads activity through Apple Health on iPhone and Health Connect on Android. A third-party source must actually write energy data PlateLens can use to resolve activity, with permissions enabled; a workout appearing in another app is not enough. Check the recorded active calories in the health platform and PlateLens. You can enter exercise manually if those calories are unavailable, taking care not to count the same workout twice.
Keep your base plan, choose your activity split
Save the targets you intend to follow and see how the recorded activity changes the day.