Why We Need Transgender Nutrition Guides

When you start with a new fitness coach, there’s a chance they will ask you to “get your labs done.” This is because blood and urine tests (“labs”) can determine levels of various hormones in your body, including reproductive, thyroid, adrenal, pituitary, and others. These hormones impact fat distribution, muscle growth, and metabolism, and their levels vary significantly among individuals within the categories male and female.

Good coaches know that hormone diversity exists and they take this into account when designing strength programs, setting macro targets, and selecting progress metrics. Simply asking you to check M or F on a client intake form may not be enough to get the results you’re after. It’s probably not a political belief. It’s just a reality they have to work with if they want to run successful businesses.

Unfortunately, Dietary Reference Intakes are still divided into “men” and “women.” In addition to complicating matters for your coach, it also leaves a critical gap in nutritional guidance for transgender and gender non-conforming people. Addressing this gap in trans health research could have positive benefits for anyone who is interested in better understanding and changing their body composition.

Hormones, Nutrition, and Body Composition

Hormone levels impact body composition—how much fat your body stores and where it is stored. Testosterone contributes to increased lean muscle mass and a reduction in fat mass, particularly in the abdominal area. Estrogen promotes fat storage in the butt, thighs, and hips.

These hormonal determinants of body composition and fat distribution patterns are well documented. Hormone replacement therapy (HRT) can dramatically shift these processes, which is how we ended up with two seemingly very different groups—transgender people and bodybuilders—among those most interested in hormone research.

Nutrition also plays a critical role in hormone production. Dietary fats synthesize steroid hormones like estrogen and testosterone. Protein supplies amino acids necessary for insulin and thyroid hormones, and carbs impact insulin, leptin, and ghrelin, which regulate blood sugar and appetite. Micronutrients like vitamin D support testosterone production, zinc aids in immune function, magnesium regulates cortisol, and iodine is essential for thyroid hormone production. Prolonged calorie deficits may lower thyroid hormones, disrupt menstrual cycles, and reduce testosterone.

Research shows that tailoring nutrition protocols to an individual’s hormone profile, lifestyle, and body composition goals—rather than their assigned sex at birth—leads to better outcomes. This is, in part, because “sex” as we normally speak about it oversimplifies biological diversity. It lumps together multiple sex characteristics (like chromosomes, hormones, and anatomy) and excludes intersex people, who make up nearly 2% of the population.

People often have natural variations in hormone levels, fat distribution, and muscle composition that don’t align with binary sex categories. For instance, someone with XY (“male”) chromosomes may have higher estrogen levels than typically expected, and someone with XX (“female”) chromosomes may have naturally elevated testosterone.

Nutrition protocols that rely solely on sex assignment at birth can lead to misinformed recommendations. Every good fitness coach already knows and incorporates this information into the plans they build for their clients, but, interestingly, we don’t actually have quality research and nutritional guidelines to support the people most impacted.

The Gap in Trans-Inclusive Nutrition Research

While many in the fitness space intuitively program nutrition and macros that account for hormone variance, outside of fitness circles there is a persistent lack of nutrition guidance for trans, intersex, and gender non-conforming people. Recommended daily amounts of most nutrients are broken down into the recommendation for men and the recommendation for women.

This research gap is a problem for multiple reasons. First, it leaves trans and GNC people (and their coaches) struggling to piece together what should be clear, evidence-based nutrition advice. A 2024 study in Nutrition in Clinical Practice found that medical providers face “uncertainty when providing medical nutrition assessments and therapies” to gender diverse people, because “many standardized guidelines and assessment tools are sex-specific.”

Second, the idea that we only need recommendations for “men” and “women” is fundamentally at odds with how fitness and nutrition coaches work with clients.

Macro Targets as Gender-Affirming Care

While research has begun to address the impact of HRT on body composition, the specific impact of HRT on macronutrient needs remains underexplored. There is, correspondingly, almost no research connecting the dots between food, hormones, and body goals for trans and GNC people.

We often hear things like “a balanced diet with fats, proteins, carbs, and micronutrients is essential for optimal hormone production.” We need to ask what is meant by “optimal hormone production,” and what specific nutritional needs are introduced when people intentionally change their hormones to achieve body goals.

We know that insufficient dietary fat can disrupt menstruation, for example. But what if you’re working with a trans man who doesn’t want their period anyway? What is the definition of “optimal hormone production” for this person?

Interestingly, the women’s bodybuilding space has a lot to offer on this topic. Many women with high-level strength goals are okay with temporarily losing their period because they have chosen to prioritize a stage competition, for example, over getting pregnant. The assumption that women need to perpetually prioritize fertility has been readily done away with in some fitness spaces. It’s a welcome (if unexpectedly feminist) development that other parts of society could learn from.

When working with a trans man client, we might instead ask:

• How much protein should he consume to match his strength training goals?

• What impact will losing his period have on other parts of his physical and mental health?

• What can we do to mitigate any of these negative adaptations, while continuing to respect that he simply doesn’t view period loss as a problem?

The knowledge gap is more than an oversight. It’s a missed opportunity to support marginalized communities and advance science for everyone. The list of possibilities, questions, and new areas of research are exciting.

Could adjusting macro or micronutrient intake for trans people on HRT optimize their hormonal balance and support body composition goals? Could research into trans health help coaches develop better fat, protein, and carb guidelines for all clients? Could macro targets that support someone’s hormone goals—without requiring medical intervention—become a form of gender-affirming care?

By addressing these gaps, we can ensure trans and GNC people have access to the same level of care and clarity as cisgender people and help clients across the spectrum get results that make them feel more at home in their bodies.