Training fasted and wondering if your pre-workout ruins your fast? The answer isn’t simple. It depends on what’s actually in your pre-workout.

You wake up. You’re fasting. Your feeding window doesn’t start for 4 hours. But you want to hit the gym now and need energy.

You reach for your pre-workout. Then pause. “Will this break my fast?” You’re confused because you’ve heard conflicting information.

You’ve been told:

• “Any supplement breaks a fast”
• “Pre-workout is fine during fasting”
• “Only caffeine is allowed”
• “BCAAs don’t count”

Most of this is oversimplified or wrong. The truth: Whether pre-workout breaks your fast depends entirely on the specific ingredients. A pre-workout with zero calories, no BCAAs, and no carbs does NOT break a fast. A pre-workout with BCAAs, maltodextrin, or significant calories DOES break your fast. You need to check the label and understand each ingredient’s metabolic impact. Most commercial pre-workouts contain at least some fast-breaking ingredients.

In this comprehensive guide, I’ll explain what actually breaks a fast (the metabolic definition), reveal which pre-workout ingredients break fasting (BCAAs, carbs, sweeteners analyzed), show you which ingredients are safe (caffeine, beta-alanine, citrulline), provide strategies for fasted training (pre-workout alternatives), and address benefits and risks of fasted pre-workout use (energy vs. side effects).

Whether you’re doing 16:8, OMAD, or any fasting protocol, understanding pre-workout compatibility is crucial.

Let’s break down pre-workout ingredients and fasting scientifically.

What Does “Breaking a Fast” Actually Mean?

The metabolic definition.

The Physiological State of Fasting

What happens during fasting:

Early fasting (0-8 hours):

• Recent meal digestion complete
• Insulin levels declining
• Beginning to use stored glycogen
• Transition phase

Deep fasting (8-16+ hours):

• Insulin at baseline (very low)
• Glycogen stores depleting
• Fat oxidation increasing
• Ketone production beginning (if prolonged)
• Autophagy activating
• Fasted metabolic state

The key metabolic markers:

• Low insulin
• Stable/low blood glucose
• Elevated fat oxidation
• Ketone production (longer fasts)
• Cellular cleanup processes active
• Fasting benefits

What Breaks a Fast (The Criteria)

Primary factor 1: Caloric intake

• Consuming calories triggers metabolic shift
• Digestive processes activated
• Shifts from fasted to fed state
• Calorie threshold

The calorie standards:

• Strict definition: 0 calories (water only)
• Practical definition: <5-10 calories (negligible)
• Flexible definition: <50 calories (maintains most benefits)
• Different approaches

Primary factor 2: Insulin response

• Insulin signals fed state
• Halts fat burning
• Stops autophagy
• Hormonal signal

What triggers insulin:

• Carbohydrates (strongest response)
• Protein (moderate response)
• BCAAs (significant response despite low calories)
• Fat (minimal response)
• Macronutrient hierarchy

The combination:

• Both calories AND insulin response matter
• Some ingredients have calories but no insulin (fats)
• Some trigger insulin despite few calories (BCAAs)
• Dual consideration

Pre-Workout Ingredients: Do They Break Your Fast?

Ingredient-by-ingredient analysis.

Ingredients That BREAK a Fast

1. BCAAs (Branched-Chain Amino Acids)

What they are:

• Leucine, isoleucine, valine
• Proteinogenic amino acids
• Common in pre-workouts
• Amino acid trio

Calorie content:

• ~4 calories per gram (like protein)
• Typical pre-workout dose: 5-7g
• ~20-28 calories
• Caloric impact

Insulin response:

• BCAAs are highly insulinogenic
• Trigger insulin release significantly
• Leucine especially potent
• Strong insulin effect

The verdict:

• BCAAs definitively break a fast
• Both calories AND insulin response
• Fasting incompatible

2. Carbohydrates (Dextrose, Maltodextrin)

What they are:

• Simple, fast-digesting carbs
• Added for energy and taste
• High glycemic index
• Sugar sources

Common amounts in pre-workouts:

• 2-10g per serving (varies widely)
• Some “pump” formulas have 20-30g
• Variable content

Calorie content:

• 4 calories per gram
• 5g carbs = 20 calories
• Caloric load

Insulin response:

• Strong and immediate
• Blood glucose spike
• Insulin released rapidly
• Major insulin trigger

The verdict:

• Carbs definitively break a fast
• Even small amounts (2-5g) cause insulin response
• Fasting incompatible

3. Protein

Rarely in pre-workout, but if present:

• 4 calories per gram
• Moderate insulin response
• Breaks fast
• Not common but possible

4. Significant Calories from Any Source

The threshold:

• 10 calories generally considered fast-breaking
• 50 calories definitely breaks fast
• Calorie limit

Check label:

• If “Calories: 15” or higher → Breaks fast
• If “Calories: 0-5” → Likely safe (but check ingredients)
• Label reading essential

Ingredients That DON’T Break a Fast

1. Caffeine

What it is:

• Stimulant from coffee beans or synthetic
• Primary active ingredient in most pre-workouts
• Energy driver

Calorie content:

• 0 calories
• Zero caloric impact

Insulin response:

• No insulin release
• May actually improve insulin sensitivity
• No hormonal disruption

Metabolic effects:

• Increases fat oxidation (beneficial for fasting)
• Enhances autophagy (doesn’t impair it)
• May suppress appetite
• Fasting-compatible metabolic effects

Typical dose in pre-workout:

• 150-300mg per serving
• Equivalent to 1.5-3 cups coffee
• Standard range

The verdict:

• Caffeine does NOT break a fast
• Actually may enhance fasting benefits
• Fasting-compatible

2. Beta-Alanine

What it is:

• Non-proteinogenic amino acid
• Buffers lactic acid
• Causes tingling sensation
• Performance enhancer

Calorie content:

• Technically has calories (like all amino acids)
• But metabolically used differently than proteinogenic amino acids
• Not used for energy or protein synthesis
• Generally considered calorie-free in context
• Functionally zero calories

Insulin response:

• No insulin trigger
• No hormonal effect

The verdict:

• Beta-alanine does NOT break a fast
• Fasting-compatible

3. L-Citrulline

What it is:

• Non-proteinogenic amino acid
• Increases nitric oxide production
• Improves blood flow
• Pump enhancer

Calorie/insulin status:

• Functionally calorie-free (like beta-alanine)
• No insulin response
• Metabolically neutral

The verdict:

• L-citrulline does NOT break a fast
• Fasting-compatible

4. Taurine

What it is:

• Non-proteinogenic amino acid
• Supports hydration and performance
• Common ingredient

Calorie/insulin status:

• Functionally calorie-free
• No insulin response
• Metabolically neutral

The verdict:

• Taurine does NOT break a fast
• Fasting-compatible

5. L-Theanine

What it is:

• Amino acid from tea
• Reduces jitters from caffeine
• Promotes calm focus
• Calming agent

Calorie/insulin status:

• Functionally calorie-free
• No insulin response
• Metabolically neutral

The verdict:

• L-theanine does NOT break a fast
• Fasting-compatible

6. Betaine

What it is:

• Compound from beets
• Supports power output
• Performance ingredient

Calorie/insulin status:

• Functionally calorie-free
• No insulin response
• Metabolically neutral

The verdict:

• Betaine does NOT break a fast
• Fasting-compatible

7. Creatine

What it is:

• Compound for ATP regeneration
• Increases strength and power
• Well-researched ergogenic

Calorie/insulin status:

• 0 calories
• No insulin response
• Metabolically neutral

The verdict:

• Creatine does NOT break a fast
• (We’ve covered this in detail in previous article)
• Fasting-compatible

8. Electrolytes (Sodium, Potassium, Magnesium)

What they are:

• Minerals for hydration and function
• Often in pre-workouts for pumps
• Mineral blend

Calorie/insulin status:

• 0 calories
• No insulin response
• Completely neutral

The verdict:

• Electrolytes do NOT break a fast
• Fasting-compatible

9. B Vitamins

What they are:

• Vitamins for energy metabolism
• Common in pre-workouts
• Micronutrients

Calorie/insulin status:

• 0 calories
• No insulin response
• Metabolically neutral

The verdict:

• B vitamins do NOT break a fast
• Fasting-compatible

The Artificial Sweetener Question

The debate:

• Do zero-calorie sweeteners trigger insulin?
• Do they “break” a fast?
• Controversial

Common sweeteners in pre-workouts:

• Sucralose
• Acesulfame-K
• Stevia
• Zero-calorie options

The research:

Some studies suggest:

• Possible minor insulin response (cephalic phase)
• Body tastes sweet, expects sugar, releases small insulin
• Potential minor effect

Other studies show:

• No insulin response
• No blood glucose changes
• No effect

The practical reality:

• Even if minor insulin response occurs, it’s very small
• Much less than actual sugar
• Impact on fat loss minimal
• Likely negligible

The conservative approach:

• Strict autophagy-focused fast: Avoid sweeteners
• Fat loss-focused fast: Sweeteners probably fine
• If concerned: Choose unsweetened pre-workout
• Risk-based decision

Most people’s approach:

• Artificial sweeteners in pre-workout acceptable
• Benefits outweigh potential minimal insulin effect
• Practical permissiveness

Does YOUR Pre-Workout Break Your Fast?

How to determine.

The Label Reading Method

Step 1: Check calorie content

• Look at “Calories:” on nutrition label
• 0-5 calories: Likely fine (check ingredients still)
• 5-10 calories: Gray area
• 10+ calories: Probably breaks fast
• Calorie threshold

Step 2: Check for BCAAs

• Look at ingredient list
• If contains: Leucine, Isoleucine, Valine, or “BCAAs”
• Breaks fast (even if low calories listed)
• BCAA check

Step 3: Check for carbs

• Look at “Total Carbohydrates:”
• 0g: Good
• 1-3g: Minimal (likely from sweeteners, probably okay)
• 5g+: Breaks fast
• Carb content

Step 4: Check for protein

• Look at “Protein:”
• 0g: Good
• Any amount: Breaks fast
• Protein content

Step 5: Assess ingredients

• Caffeine, beta-alanine, citrulline, taurine, creatine, betaine: All fine
• BCAAs, carbs, protein: Break fast
• Ingredient evaluation

Common Pre-Workouts Evaluated

Example 1: C4 Original

• Calories: 0
• Carbs: 0g
• Protein: 0g
• No BCAAs
• Verdict: Does NOT break fast

Example 2: Pre JYM

• Calories: 5
• Contains BCAAs (6g)
• Verdict: BREAKS fast (due to BCAAs despite low calories)

Example 3: Legion Pulse

• Calories: 0
• Carbs: 0g
• No BCAAs
• Verdict: Does NOT break fast

Example 4: Pre-workout with carbs (some pump formulas)

• Calories: 80
• Carbs: 20g
• Verdict: Definitely BREAKS fast

The pattern:

• Many basic stimulant-focused pre-workouts: Safe
• Pre-workouts with BCAAs: Break fast
• Pre-workouts with carbs: Break fast
• Check your specific product

Benefits of Pre-Workout During Fasting

Why use it while fasted.

Benefit 1: Energy and Focus

The fasted training challenge:

• No recent food intake
• Lower glycogen stores
• Reduced energy for training
• Mental fog possible
• Energy deficit

How pre-workout helps:

• Caffeine provides energy and alertness
• Improves focus and concentration
• Enhances mind-muscle connection
• Offsets fasted fatigue
• Performance support

The research:

• Caffeine improves performance regardless of fed/fasted state
• May be even more valuable when fasted (compensates for energy deficit)
• Evidence-based benefit

Benefit 2: Faster Absorption

The mechanism:

• Empty stomach = faster absorption
• No food competing for absorption
• Ingredients enter bloodstream quicker
• Accelerated uptake

The timeline:

• Fasted: Feel effects in 10-20 minutes
• Fed: Feel effects in 30-45 minutes
• Time difference

The advantage:

• Can take pre-workout closer to training
• More precise timing
• Peak effects during workout
• Timing optimization

Benefit 3: Enhanced Fat Oxidation

The synergy:

• Fasted state: Already burning fat for fuel
• Caffeine: Increases fat oxidation further
• Combined effect greater than either alone
• Synergistic fat burning

The research:

• Caffeine enhances lipolysis (fat breakdown)
• Effect magnified in fasted state
• May support fat loss goals
• Fat loss benefit

Benefit 4: Maintained Training Performance

The importance:

• Training quality crucial for muscle retention during cut
• Fasted training can compromise performance
• Pre-workout preserves intensity
• Performance maintenance

The benefit:

• Maintain strength and volume despite calorie deficit
• Better muscle preservation
• More effective cut
• Training quality support

Risks of Taking Pre-Workout on Empty Stomach

Potential side effects.

Risk 1: GI Distress

The problem:

• Pre-workout on empty stomach can cause nausea
• Cramping possible
• Digestive discomfort
• Stomach sensitivity

Who’s affected:

• People with sensitive stomachs
• Those taking high-stimulant pre-workouts
• Individual variation
• Not everyone

Why it happens:

• Concentrated ingredients without food buffer
• Caffeine stimulates gastric acid production
• Beta-alanine can irritate on empty stomach
• Multiple factors

The solutions:

Solution 1: Start with half dose

• Assess tolerance
• Increase if tolerated
• Conservative approach

Solution 2: Take with small amount food

• 5-10g protein or small piece fruit
• Technically “breaks” fast but minimally
• Eliminates GI issues
• Trade-off option

Solution 3: Choose different pre-workout

• Lower stimulant content
• Fewer irritating ingredients
• Product switch

Solution 4: Take earlier

• 30-45 minutes before training (instead of 15-20)
• More time to settle
• Timing adjustment

Risk 2: Jitters and Anxiety

The problem:

• Caffeine on empty stomach hits harder
• Excessive jitters possible
• Anxiety or nervousness
• Racing heart
• Overstimulation

Who’s affected:

• Caffeine-sensitive individuals
• Those taking high-dose pre-workouts (300mg+ caffeine)
• Susceptible people

The solutions:

Solution 1: Lower dose

• Half serving of pre-workout
• Or switch to lower-caffeine product
• Dose reduction

Solution 2: Add L-theanine

• Many pre-workouts include this
• Reduces jitters from caffeine
• Calming agent

Solution 3: Avoid if too sensitive

• Some people just can’t tolerate fasted caffeine
• Train fasted without pre-workout instead
• Skip it

Risk 3: Blood Sugar Drop

The rare problem:

• Some people experience reactive hypoglycemia
• Blood sugar drops after caffeine
• Shakiness, weakness, lightheadedness
• Uncommon but possible

Who’s affected:

• People with blood sugar regulation issues
• Very sensitive individuals
• Minority

The solution:

• Small amount fast-acting carbs before training
• Breaks fast slightly but prevents issue
• Or avoid fasted training entirely
• Safety first

Risk 4: Headaches

The problem:

• Fasted + caffeine = headaches for some
• Dehydration contribution
• Discomfort

The solution:

• Ensure adequate hydration
• Drink 16-20 oz water with pre-workout
• Electrolytes may help
• Hydration focus

Strategies for Fasted Training

Practical approaches.

Option 1: Fasting-Compatible Pre-Workout

The approach:

• Choose pre-workout with no BCAAs, no carbs, no protein
• Take as normal (30-45 min before training)
• Maintains fasted state
• True fasted training

Recommended products:

• C4 Original
• Legion Pulse
• Transparent Labs PreSeries Lean
• Any caffeine + citrulline + beta-alanine formula without BCAAs/carbs
• Fasting-friendly options

Option 2: DIY Caffeine Stack

The approach:

• Skip commercial pre-workout
• Make your own from individual ingredients
• Custom blend

The stack:

• 200mg caffeine (pill or black coffee)
• 5g citrulline malate (optional, for pumps)
• 3g beta-alanine (optional, for endurance)
• 5g creatine (optional, can take anytime)
• Simple and fasting-compatible

The advantage:

• Complete control over ingredients
• Zero risk of hidden BCAAs or carbs
• Often cheaper
• Maximum certainty

Option 3: Just Black Coffee

The minimalist approach:

• 1-2 cups black coffee
• 95-190mg caffeine
• 0 calories
• Simplest option

The benefits:

• Definitely doesn’t break fast
• Cheap
• Effective
• Natural
• Classic choice

The limitations:

• No other performance ingredients (citrulline, beta-alanine)
• Lower caffeine than many pre-workouts
• Basic but works

Option 4: Train Completely Fasted (No Pre-Workout)

The purist approach:

• No supplements at all
• Just water
• True fasted training

When this works:

• If training intensity doesn’t suffer
• If energy levels adequate
• If you don’t need stimulation
• Individual tolerance

The consideration:

• Performance may be suboptimal
• But some people train fine fasted
• Personal variation

Option 5: Small Pre-Workout Meal (Break Fast Slightly)

The compromise:

• Small amount protein + carbs before training
• 10-20g protein, 10-20g carbs
• Take pre-workout with this
• Minimal fast-breaking

When this makes sense:

• If fasted training causes too many issues
• If performance suffering significantly
• If GI distress bad
• Practical compromise

The example:

• Banana + 1 scoop whey (or equivalent)
• Wait 30 min, then train
• Technically breaks fast but enables quality training
• Trade-off decision

Common Questions

Addressing confusion.

“Will taking pre-workout during my fast ruin my fat loss?”

The answer:

• If pre-workout has no calories/BCAAs/carbs: No, won’t impact fat loss
• If has small amounts (5-20 cal): Minimal impact, likely fine
• Fat loss primarily about total daily calories
• Bigger picture matters

The perspective:

• Don’t sabotage training quality to be ultra-strict about fasting
• Quality training preserves muscle during cut
• More important than perfect fasting
• Priorities

“Can I take pre-workout during a 24+ hour fast?”

The answer:

• Yes, if it’s fasting-compatible (no BCAAs, carbs, calories)
• Caffeine may be even more helpful during extended fasts
• Extended fast compatible

The consideration:

• Caffeine on very empty stomach (24+ hours) might cause more GI issues
• Start with lower dose
• Increased sensitivity

“Should I take pre-workout before fasted cardio?”

The answer:

• Caffeine helps with fasted cardio performance
• Fat oxidation may be enhanced
• Can be beneficial

The note:

• Pre-workout designed for resistance training
• For cardio, might just need caffeine (not all the other ingredients)
• Black coffee might be sufficient
• Adjust to activity

“Does pre-workout break ketosis?”

The answer:

• If it contains carbs: Yes, temporarily
• If it’s carb-free: No, maintains ketosis
• Carb-dependent

For keto + IF:

• Choose zero-carb pre-workout
• Maintains both ketosis and fasting state
• Double compatible

“Will pre-workout impair autophagy?”

The answer:

• Fasting-compatible pre-workout (no BCAAs, carbs, protein): Does not impair autophagy
• BCAAs or protein: May reduce autophagy (insulin response)
• Ingredient-dependent

For autophagy-focused fasts:

• Very strict: Avoid all supplements, water only
• Moderate: Caffeine and non-caloric ingredients okay
• Strictness level

The Bottom Line: Check Your Pre-Workout’s Label

After explaining everything:

The truth about pre-workout and intermittent fasting:

✅ Whether pre-workout breaks your fast depends on specific ingredients (not all pre-workouts are the same)

✅ BCAAs and carbs break a fast (insulin response and calories)

✅ Caffeine, beta-alanine, citrulline, creatine do NOT break fast (zero calories, no insulin)

✅ Many commercial pre-workouts are fasting-compatible (if they don’t contain BCAAs or carbs)

✅ Benefits often outweigh risks for fasted training (energy and performance support)

Key takeaways:

What breaks a fast:

• Caloric intake (generally >10 calories)
• Insulin response (from carbs, protein, BCAAs)
• Dual criteria

Pre-workout ingredients that BREAK fast:

• BCAAs (leucine, isoleucine, valine): Highly insulinogenic despite low calories
• Carbohydrates (dextrose, maltodextrin): 2-10g typical, triggers insulin
• Protein: If present (rare in pre-workout)
• 10 calories from any source
• Fast-breakers

Pre-workout ingredients that DON’T break fast:

• Caffeine: 0 calories, no insulin, may enhance fasting benefits
• Beta-alanine: Non-proteinogenic, functionally calorie-free
• L-citrulline: Non-proteinogenic, no insulin
• Taurine: No insulin or calories
• L-theanine: Calming agent, fasting-safe
• Betaine: Performance enhancer, fasting-safe
• Creatine: 0 calories, no insulin
• Electrolytes: Minerals, completely neutral
• B vitamins: Micronutrients, no impact
• Fasting-compatible ingredients

Artificial sweeteners:

• Sucralose, acesulfame-K, stevia common
• Debate exists (possible minor insulin response)
• Practically: Impact likely minimal
• Conservative: Avoid if strict autophagy focus
• Flexible: Generally acceptable
• Gray area, likely fine

How to check YOUR pre-workout:

1. Check calories (0-5 = likely okay, 10+ = breaks fast)
2. Check for BCAAs in ingredients (if present = breaks fast)
3. Check carbs (0-1g okay, 5g+ = breaks fast)
4. Check protein (0g = okay, any amount = breaks fast)
5. Evaluate individual ingredients

• Label reading process

Common pre-workouts:

• C4 Original, Legion Pulse: Fasting-compatible (no BCAAs/carbs)
• Pre JYM: Breaks fast (contains BCAAs)
• Pump formulas with carbs: Break fast
• Check specific product

Benefits of fasted pre-workout:

• Energy and focus (caffeine offsets fasted fatigue)
• Faster absorption (empty stomach = quicker effects)
• Enhanced fat oxidation (synergy with fasted state)
• Maintained training performance (preserves intensity)
• Performance support

Risks/side effects:

• GI distress (nausea, cramping in sensitive individuals)
• Jitters and anxiety (caffeine hits harder fasted)
• Blood sugar drop (rare, hypoglycemia-prone people)
• Headaches (dehydration factor)
• Manageable with dose adjustment

Risk management:

• Start with half dose
• Ensure hydration (16-20 oz water)
• Take 30-45 min before training (not right before)
• Choose lower-stim if sensitive
• Gradual approach

Fasted training strategies:

Option 1: Fasting-compatible commercial pre-workout (C4, Legion Pulse) Option 2: DIY stack (caffeine + citrulline + beta-alanine) Option 3: Black coffee only (simplest) Option 4: Train completely fasted (no supplements) Option 5: Small pre-workout meal (breaks fast slightly but supports performance)

• Multiple approaches

Priority actions:

1. Read your pre-workout label (check calories, BCAAs, carbs)
2. If contains BCAAs or 5g+ carbs: Breaks fast (move to feeding window or switch products)
3. If 0 calories, no BCAAs, no carbs: Safe during fast
4. Start with half dose if taking fasted (assess tolerance)
5. Hydrate well (16-20 oz water with pre-workout)
6. Time 30-45 min before training

• Implementation checklist

CHECK YOUR PRE-WORKOUT LABEL. NO BCAAS, NO CARBS, 0-5 CALORIES = FASTING-COMPATIBLE. BCAAS OR CARBS = BREAKS FAST. CAFFEINE, BETA-ALANINE, CITRULLINE ARE SAFE.

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Ready to optimize your entire fasted training protocol with evidence-based supplement timing, performance strategies, and nutrition systems that maximize fat loss while preserving muscle and training intensity? Understanding pre-workout compatibility is just one piece. Get comprehensive fasted training guidance. Stop guessing about supplements. Start fasting strategically.

REFERENCES

SECTION 1 — What Does “Breaking a Fast” Actually Mean?

[1] de Cabo R, Mattson MP. — New England Journal of Medicine, 2019 Effects of Intermittent Fasting on Health, Aging, and Disease https://www.nejm.org/doi/full/10.1056/NEJMra1905136

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SECTION 2 — BCAAs Break a Fast (Insulin Response + Calories)

[2] Yang J et al. — PubMed / Journal of Biological Chemistry, 2012 Leucine stimulates insulin secretion via down-regulation of surface expression of adrenergic α2A receptor through the mTOR pathway https://pubmed.ncbi.nlm.nih.gov/22645144/

[3] Yoshikawa et al. — Nutrition & Diabetes (Nature Portfolio), 2024 BCAAs acutely drive glucose dysregulation and insulin resistance https://pubmed.ncbi.nlm.nih.gov/38844453/

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SECTION 3 — Carbohydrates Break a Fast

[4] Labonté CC et al. — Frontiers in Nutrition, 2021 Plasma BCAAs Are Associated With Greater Fasting and Postprandial Insulin Secretion https://pubmed.ncbi.nlm.nih.gov/33996878/

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SECTION 4 — Caffeine Does NOT Break a Fast + Fat Oxidation

[5] Collado-Mateo D et al. — Nutrients (MDPI), 2020 Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis https://pubmed.ncbi.nlm.nih.gov/33255240/

[6] Fernández-Sáez J et al. — Nutrients (MDPI), 2024 Effect of Acute Caffeine Intake on Fat Oxidation Rate during Fed-State Exercise: A Systematic Review and Meta-Analysis https://pubmed.ncbi.nlm.nih.gov/38257100/

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SECTION 5 — The Artificial Sweetener Debate

[7] Pepino MY et al. — Diabetes Care, 2013 Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load https://pubmed.ncbi.nlm.nih.gov/23633524/

[8] Dalenberg JR et al. — Cell Metabolism, 2020 Short-Term Consumption of Sucralose with, but Not without, Carbohydrate Impairs Neural and Metabolic Sensitivity to Sugar in Humans https://www.cell.com/cell-metabolism/fulltext/S1550-41312030057-7

[9] Lertrit A et al. — Nutrition, 2018 Effects of sucralose on insulin and glucagon-like peptide-1 secretion in healthy subjects: a randomized, double-blind, placebo-controlled trial https://pubmed.ncbi.nlm.nih.gov/30005329/