The Missing Half of the Nutrition Research

Most of what we're told about how to eat around exercise was learned from men. Not as a slur on the science — simply as a fact of who showed up in the studies. Which raises a quiet question worth sitting with: if the guidelines were built on someone else's physiology, how confident should the other half of the population be in them?

A narrative review published in late 2025 makes the gap explicit. Nutrition is a key factor in exercise and sport performance, but much of the research underpinning dietary and nutrient recommendations was conducted only in men [1]. The distinct physiological, neurological, and hormonal changes across a woman's life cycle significantly affect nutritional needs, and yet current dietary frameworks largely lack sex-specific guidelines for calories, carbohydrates, fats, proteins, and several supplements [1]. That is a notable admission from within the field: not that women have been studied and found similar, but that in many places they have not been studied enough to say.

This matters most in the areas where women's physiology genuinely diverges. Consider bone. Estrogen plays a central role in bone development and loss, which leaves women with lower peak bone mass and a higher fracture risk, particularly after menopause [5]. Resistance and weight training are among the most effective strategies to maintain bone health across that transition [5]. And yet a 2026 paper in Annals of Medicine argues that societal biases — misconceptions about excessive muscle gain, a supposed loss of femininity — still deter many women from picking up the weights that would most directly protect them [5]. The nutritional blind spot and the cultural one point in the same direction: an intervention with clear benefit is under-used, and the evidence base that would refine it is thin.

None of this means the general principles collapse. Nutrition supports every bodily process, from energy production to tissue maintenance, and that is true regardless of sex [3]. The point is subtler. Where the physiology is shared, borrowing recommendations from male-dominated research is defensible. Where it isn't — around hormonal cycles, bone loss, energy availability across life stages — a recommendation calibrated on men may simply be the wrong dose of the right idea. The review's contribution is to mark those boundaries rather than pretend they don't exist [1].

The supplement conversation is where this restraint is hardest to hold, because supplements are where marketing runs furthest ahead of evidence. A 2026 systematic review and network meta-analysis set out to compare dietary protein, creatine, and omega-3 supplementation on strength, endurance, and recovery, restricting itself to randomized trials in people who had trained for at least six months [6]. That it takes a formal evidence synthesis to rank three of the most-studied supplements should temper anyone's confidence about the dozens of less-studied ones. And two recent Sigma Nutrition episodes make the same case from the demand side. One examines how electrolytes went from a specific tool for certain endurance athletes to a marketed everyday requirement for hydration, focus, and general optimisation — an example, the hosts argue, of industry taking a real mechanism and extending it far beyond the evidence [4]. Another questions the popular belief that repeated sweet-taste exposure strengthens sweet preference and drives intake, and therefore that you must "reset" your palate by avoiding sweetness — a causal chain the episode suggests the evidence does not cleanly support [2].

The connective tissue across all of it is a single discipline: compared to what? A June 2026 episode on food substitution models makes the point directly — increasing one food in a diet almost always displaces another, so the health question is never about a food in isolation but about the trade it represents [7]. That framing quietly dismantles the "good food, bad food" scoreboard. It also applies to research design: a recommendation is only as good as the population it was tested against, and the honest answer for a lot of women's nutrition is that the comparison group looked nothing like them [1].

So the sustainable move is not a new protocol. It's a posture. Lift, because the bone benefit for women is well established [5]. Eat enough to support the work [3]. Treat the supplement aisle and the electrolyte sachet as claims to be interrogated, not requirements to be met [4]. And hold the guidelines loosely where the science admits it hasn't done its homework [1].

Research Radar

• The guidelines have a sex gap. A 2025 narrative review found that many nutrition and nutrient recommendations for athletes derive from research conducted only in men, despite hormonal and physiological differences that shape women's needs — and it flags the absence of sex-specific frameworks [1].
• Weights protect women's bones. Because estrogen's role leaves women with lower peak bone mass and higher fracture risk after menopause, resistance training is a leading strategy to maintain bone health — one that cultural bias still discourages [5].
• Electrolytes, reconsidered. A 2026 discussion traces how electrolyte products moved from a niche endurance tool to an everyday "requirement," arguing many common use cases are unlikely to need supplementation at all [4].

One Thing To Try

Before your next supplement or electrolyte purchase, ask one question out loud: compared to what? [7] What would this replace, and is there a trial in people like me showing it beats that? [6] If you can't answer, that's information too.

Worth Your Attention

• Nutrition Considerations for Female Athletes — the review naming the research gap directly, and a useful map of where male-derived advice may not transfer [1].
• Strength unseen (Annals of Medicine) — a clear-eyed case for why women's resistance training is under-used, and the bone science behind it [5].
• Sigma Nutrition #611, Electrolyte Mythology — a careful separation of the real physiology from the wellness marketing built on top of it [4].
• Sigma Nutrition #610, Rock, Paper, Salmon — why "compared to what?" is the question that quietly fixes most food debates [7].

The better answer to a guideline built for someone else's body isn't outrage or dismissal. It's the same modest question the substitution researchers keep returning to: compared to what? [7] Held gently, that question makes the whole field easier to live inside — no extremes, no reset, no guilt. Just a willingness to ask whether the advice was ever meant for you, and to keep lifting while the science catches up [5].