The Importance of Building Muscle and Strength on Metabolic Health

​To make muscle and strength a true health strategy you need repeatable metrics: compound‑lift strength and clinical strength tests and run an annual whole‑body DXA scan to track lean and fat mass over years. Lower strength is consistently associated with worse cognitive outcomes, and nutritional and exercise‑centric multidomain trials support cognition-preserving strategies. (PMID: 25771249; PMC: PMC7890203).

You can build muscle on a lower carb diet if the training and protein are right. A low‑carb or ketogenic diet does not inherently prevent hypertrophy, which is a question that comes up frequently. What builds muscle is the same on any diet: a mechanical stimulus (progressive training), sufficient amino acids (protein), and enough energy to recover and adapt. In resistance‑trained men, an isocaloric, isonitrogenous randomized trial comparing a ketogenic diet with a Western diet found lean body mass increased in both groups, and strength/power changes were broadly comparable during the training period. (PMID: 28399015). Across multiple studies, meta‑analytic evidence supports the practical conclusion that resistance‑training athletes can maintain and often increase fat‑free mass on ketogenic diets—especially when calories aren’t inadvertently too low and protein is sufficient. (PMID: 33624538; PMC: PMC9564904). A key nuance clinicians should communicate: body composition readouts can shift due to glycogen and water changes when carbohydrate intake changes. That doesn’t mean “muscle disappeared”—but it can influence short‑term DXA/FFM readings and how patients interpret early results. Longitudinal tracking (especially with standardized testing conditions) is the antidote. (PMC: PMC5659281).

Protein has a new baseline: DGA 2025–2030 recommends 1.2–1.6 g/kg/day. The most important lever is protein quantity. The DGA 2025–2030 provides a clear body‑weight-based target: 1.2–1.6 grams of protein per kilogram of body weight per day, and explicitly encourages prioritizing protein foods at every meal. This matters for muscle and aging since sarcopenia is not just “less muscle”; it is strongly driven by declining strength and functional reserve. The European consensus (EWGSOP2) explicitly focuses on low muscle strength as the key characteristic of sarcopenia, using muscle quantity to confirm and performance to stage severity. (PMID: 30312372; PMC: PMC6322506).

Practical translation for patients:
70 kg adult → 84–112 g/day (1.2–1.6 g/kg/day)
90 kg adult → 108–144 g/day
This protein target is compatible with ketogenic diets. In fact, because keto often reduces appetite and total calories for some people, it’s even more important to deliberately “hit protein” to avoid drifting into a low‑energy/low‑protein state that undermines training adaptation. (PMID: 33624538).

It is important to "audit" strength: don’t guess—measure it with repeatable tests
If you want muscle to function as a health investment, you need a recurring “audit” the same way you’d audit blood pressure or A1c. The most useful approach is to combine gym‑specific strength metrics with clinical strength/performance tests. Gym metrics are major compound lifts as repeatable performance biomarkers. For trained or training‑ready adults, choose 3–4 movement patterns that represent whole‑body capacity:

Squat pattern (back squat, safety‑bar squat, leg press if needed)
Hinge (deadlift or trap‑bar deadlift; hip hinge variations)
Press (bench/incline press; overhead press as appropriate)
Pull (row/pull‑down/pull‑up progression)
Use either a true 1RM or a safer 3–5RM (or a consistent submax protocol to estimate 1RM). The key is repeatability. A systematic review of 1RM test–retest reliability found the 1RM is generally good to excellent in reliability, across sex, age, exercise selection, and training status, when properly executed. (PMID: 32681399; PMC: PMC7367986).

Clinical metrics include grip strength and chair stand. EWGSOP2 highlights handgrip strength and the chair stand test as practical measures of muscle strength for sarcopenia detection, and these are often more feasible than barbell testing in older adults or in medical settings. (PMID: 30312372; PMC: PMC6322506). A simple clinic‑friendly strength audit can be Grip strength (best of 2–3 trials per hand, standardized position) and Five‑times chair stand (time to complete, standardized chair height).
Optional: gait speed or Timed Up and Go for broader mobility context (if clinically needed)

Annual whole‑body DXA to assess body‑composition keeps you honest and is a great motivator. Scale weight cannot tell whether a patient gained muscle, lost muscle, or simply shifted water. Whole‑body DXA (DEXA) is one of the most standardized tools for longitudinal body‑composition tracking, widely used in research and clinical contexts. (PMC: PMC5659281). Meaningful changes in lean mass and fat mass usually occur over months, not days. Annual DXA emphasizes trend, reduces overreaction to noise, and aligns well with the timeframe of real behavior change (training blocks, nutrition changes, aging trajectory). (PMC: PMC5659281).

Muscle and strength aren’t just about metabolism since they correlate with brain health and cognition. The muscle–brain relationship is no longer speculative. Large longitudinal evidence shows that lower handgrip strength is associated with higher risk of cognitive decline and dementia, including Alzheimer’s disease. (PMC: PMC7890203; PMID: 35013908). Importantly, we also have intervention evidence that aligns with this observational signal. The FINGER trial (a landmark randomized trial) demonstrated that a multidomain intervention (diet, exercise, cognitive training, vascular risk monitoring) could improve or maintain cognitive functioning in at‑risk older adults. (PMID: 25771249; doi:10.1016/S0140-6736(15)60461-5). Meanwhile, a systematic review/meta‑analysis focused on resistance training interventions found resistance training improved cognitive function in older adults across cognitive statuses. (PMID: 33325273).
So when you help a patient gain muscle and strength, you’re not only improving glucose handling and mobility; you may also be building resilience in the systems most tied to long‑term independence: gait, balance, executive function, and the capacity to recover after illness or injury. (PMC: PMC7890203; PMID: 25771249). The clinician’s takeaway: treat strength and lean mass like vital signs of aging—because they are measurable, modifiable, and strongly linked to outcomes that patients care about. (PMID: 30312372; PMC: PMC6322506).

Dominic D'Agostino KetoNutrition, Ketone Ester, Ketone Research, Ketone Supplementation, Ketone Technologies

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