Nutrition

Why measured data changes nutrition targets

Most nutrition recommendations begin with total body weight or an estimated metabolic rate. Both introduce error. Body weight does not distinguish lean mass from fat mass. Predictive equations for resting metabolic rate can deviate meaningfully from measured values, particularly in people with atypical body composition or a history of repeated dieting.

Arbiter Wellness anchors nutrition recommendations to two measured quantities:

• Lean mass from DEXA — the primary determinant of protein requirements and a major contributor to basal energy expenditure.
• True resting metabolic rate from indirect calorimetry — the actual energy cost of maintaining physiological function at rest.

Protein precision

Protein targets are scaled to DXA-verified lean mass rather than total body weight. This better matches the substrate available for muscle protein synthesis and supports the goal of building or preserving lean tissue.

A practical range often used is approximately 1.0–1.4 grams of protein per pound of measured lean mass, adjusted according to training status, age-related considerations, and the specific goal (lean-mass gain, maintenance during fat loss, or preservation with aging).

Energy balance

Energy recommendations begin with measured resting metabolic rate and are then adjusted for activity level and training load. Because the starting number is measured rather than estimated, the resulting targets are less likely to produce unintended under- or over-fueling.

An important practical rule: caloric intake should not create extreme deficits. Dropping intake more than roughly 500 kcal below measured total daily energy expenditure increases the risk of impairing muscle retention and bone remodeling — both of which the Activity pillar is working to improve.

Metabolic flexibility context

Respiratory exchange ratio from calorimetry provides insight into substrate preference at rest. When the data indicate heavier reliance on carbohydrate even at rest, greater emphasis is often placed on improving fat-oxidation capacity through appropriate conditioning volume (see Activity) alongside nutrition.

Integration with the other pillars

Nutrition recommendations are never issued in isolation. They are coordinated with the resistance-training plan (to support lean-mass adaptation) and with sleep and recovery guidance (to ensure energy availability and hormonal environment support the intended adaptations).