7 Hidden Acne Triggers Hiding in Your Wellness Routine

‍Quick answer: Several common "healthy" habits, overtraining, fasted workouts, whey protein, BCAA supplements, shakes or snacks, high-sugar snacks, overwashing, morning coffee and poorly-timed intermittent fasting, can all raise cortisol, insulin or IGF-1, the hormonal pathways that drive the pathways behind acne. None of these are inherently bad. The issue is usually dose, timing and individual sensitivity, not the habit itself.

Exercise is medicine, until it becomes a stressor. Most of what's listed below isn't something to cut out entirely. It's something to look at honestly, because the wellness habits that are supposed to be helping your body can sometimes be quietly working against your skin.

01 — Training Too Hard, or Training on Empty

Over-training and fasted sessions both signal danger to the body, raising cortisol and keeping it there. Sebaceous glands carry receptors for cortisol and corticotropin-releasing hormone, so when cortisol stays elevated, sebum production rises with it, while ceramide synthesis, part of what keeps your skin barrier intact, gets supressed.¹ A systematic review of overtraining syndrome in athletes confirms the pattern: sustained training overload disrupts the body's normal cortisol rhythm, the very system meant to keep stress hormones in check.²

The Science: Cortisol → sebum overproduction + barrier breakdown

02 — Your Protein Powder

Whey digests fast and spikes both insulin and IGF-1, activating the mTORC1 pathway, a key driver of sebum production and follicular hyperkeratinisation.³ Not everyone reacts, this is a known and well-studied mechanism, but it isn't universal. For acne-prone skin, though, it can be an accelerant hiding in a shaker bottle. A 2024 case-control study found a significant association between whey protein supplementation and acne in young men, particularly with higher daily intake.⁴

The Science: mTORC1 activation → excess sebum + blocked follicles

03 — The "Healthy" Snack

Dates, raisins, dried mango, concentrated fruit sugars hit the bloodstream fast. The insulin surge that follows increases androgen activity and sebum output. High glycaemic load is one of the most consistent dietary patterns linked to acne in the research, a landmark randomised controlled trial found that participants on a low-glycaemic-load diet saw meaningful improvements in acne severity within just twelve weeks.⁵

The Science: Blood sugar spike → insulin → androgenic sebum drive

04 — Washing Your Face Too Often

Sky dry after washing, or that squeaky-clean feeling, is your skin telling you something went wrong. Overwashing strips the acid mantle, the skin's naturally acidic shield and disrupts the microbiome that keeps acne-associated bacteria in balance.⁶ In response, the skin overproduces oil. And so the cycle continues.

The Science: Disrupted acid mantle → microbiome imbalance → compensatory sebum

05 — Coffee, Especially First Thing

Caffeine stimulates the adrenal glands via the pituitary, raising cortisol, particularly when layered on top of the body's natural morning cortisol peak.⁷ For hormonally sensitive skin, or anyone already running on stress, this can be the quiet thread that keeps pulling.

The Science: Caffeine → cortisol spike → sebum + inflammation

06 — Protein Drinks With Added BCAAs

Branched-chain amino acids, especially leucine, are potent mTORC1 activators. This isn't theoretical. A 2023 study measuring serum amino acids found that people with acne had significantly higher circulating levels of leucine, isoleucine and valine than people without it, with a clear positive correlation between these levels and both acne severity and scarring.⁸ These amino acids can show up in some "clean" or plant-based blends too, so it's worth checking your label rather than assuming.

The Science: BCAAs → mTORC1 → acne severity (check your label)

07 — Intermittent Fasting (When It's Not Right for You)

For some, fasting genuinely helps. For others, it's an unrecognised stressor, raising cortisol, depleting micronutrients, and creating the conditions where skin suffers. Research on intermittent fasting consistently shows it raises cortisol levels and can shift the body's natural cortisol rhythm, even outside of conscious stress.⁹ The body doesn't distinguish between a wellness protocol and famine. Under-nourishment speaks its own language.

The Science: Fasting stress → cortisol elevation → skin impact

FAQ: Lifestyle Triggers and Acne ‍

Do I need to stop all of these to clear my skin?

No. These are mechanisms worth understanding, not a list of bans (although I will negotiate with clients on coffee!). Most people can tolerate moderate amounts of any one of these. Problems tend to show up when several stack together, alongside an already-stressed system.

Is whey protein definitely bad for acne-prone skin?

Not for everyone, but it's a well-documented trigger for some. If you're acne-prone and using it daily, it's worth trialling a break or switching to a plant-based alternative to see whether your skin responds. Drop me a quick email if you’d like a recommendation.

Can drinking coffee really affect acne?

Caffeine reliably raises cortisol, particularly first thing in the morning when your natural cortisol is already at its daily peak. For most people this is a minor, temporary effect, but for hormonally sensitive or already-stressed skin like most of my clients, it can add up.

Is intermittent fasting bad for skin?

Not inherently, some people do well with it. The issue is when fasting becomes another stressor layered on top of existing stress, training and under-eating. The body reads fasting and famine through the same hormonal pathway.‍ ‍

Acne Is Rarely Just One Thing

It's a pattern, nutritional, hormonal, topical, and finding it is the work. Rarely is acne caused by a single habit on this list. More often it's two or three of these quietly stacking on top of each other, alongside whatever else is going on in your life. That's exactly why generic advice so often falls short.

I help clients work through this properly through my Inside & Out Method, looking at what's happening nutritionally, hormonally and topically, together, not in isolation.

If you'd like help figuring out your own pattern, book a free 20-minute clarity call →. No quick fixes, just a clear-eyed look at what's actually going on with your skin.

‍ ‍

¹ Stress and skin diseases: overview using acne vulgaris as an example. Aesthetic Cosmetology and Medicine. 2023.‍ ‍

² Cadegiani FA, Kater CE. Hormonal aspects of overtraining syndrome: a systematic review. BMC Sports Sci Med Rehabil. 2017.

³ Melnik BC. Potential role of FoxO1 and mTORC1 in the pathogenesis of Western diet-induced acne. Exp Dermatol. 2013;22(5):311-315.

⁴ Muhaidat J, et al. The Effect of Whey Protein Supplements on Acne Vulgaris among Male Adolescents and Young Adults: A Case-Control Study from North of Jordan. Dermatol Res Pract. 2024.

⁵ Smith RN, Mann NJ, Braue A, Mäkeläinen H, Varigos GA. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007;86(1):107-115.

⁶ From Discovery to Modern Understanding: The Acid Mantle in Dermatology. J Integrative Dermatol. 2024.

⁷ Lovallo WR, Whitsett TL, al'Absi M, Sung BH, Vincent AS, Wilson MF. Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels. Psychosom Med. 2005;67(5):734-739.

⁸ Balik ZB, et al. Relationship between serum amino acid levels and acne severity. J Radiat Res Appl Sci. 2023;16(4).‍ ‍

⁹ Al-Rawi N, et al. Effect of diurnal intermittent fasting during Ramadan on ghrelin, leptin, melatonin, and cortisol levels among overweight and obese subjects. PLoS One. 2020;15(8):e0237922.