What 'good nutrition' actually is
Nutrition science is messy — food-frequency questionnaires are imperfect, long-running RCTs are expensive — but the signals that make it through the noise are fairly stable. A lot of minimally processed plant food, enough protein, healthy fats and limiting refined carbohydrates improve cardiovascular and metabolic outcomes in almost every large review.1,3,8
The Mediterranean pattern — extra-virgin olive oil, nuts, legumes, fish, vegetables, limited red meat — is the best validated of these. Trichopoulou's Greek cohort showed that strict adherence predicts roughly 25% lower all-cause mortality over ten years.8 PREDIMED later confirmed this in a randomised setting for hard cardiovascular endpoints.1
Protein — the underrated pillar
The official RDA (~0.8 g/kg body weight per day) is a floor to avoid deficiency, not an optimum for health. For most active adults the optimum sits between 1.2 and 1.6 g/kg per day — spread across the day in 25-40 g portions.4
The importance rises with age. From around 50 onwards, muscle mass drops about 1% per year without sufficient protein plus resistance training. The PROT-AGE group therefore recommends 1.0-1.2 g/kg per day for older adults, with more during illness or training goals.5 Muscle mass is one of the strongest predictors of long-term health (see also the Exercise guide).
Fibre, fat and carbohydrates
Fibre is one of the best-supported nutritional levers. The Lancet meta-analysis by Reynolds showed that 25-29 g of fibre per day is associated with 15-30% lower mortality from cardiovascular disease and type 2 diabetes — an effect larger than many medications.2 Sources: whole grains, legumes, vegetables, fruit and nuts.
On fats the direction is clear: drop trans fats (industrial hydrogenation),7 limit saturated fat when apoB is elevated, and increase unsaturated fats — particularly monounsaturated (olive oil, nuts) and omega-3 (fatty fish twice a week). Refined carbs and sugars (white bread, soft drinks, snacks) raise triglycerides and HbA1c; swapping them for whole grains and legumes reverses that.3
What nutrition does — measurably
The advantage of nutrition is that the effects are measurable. The cholesterol profile (apoB, LDL, HDL, triglycerides) responds to a shift in fat and fibre intake within 4-8 weeks. HbA1c follows over 8-12 weeks with fewer refined carbs. Ferritin and B12 are direct outcomes of what you eat.
The Optimize Baseline measures these markers together and reads them against optimal ranges — not just 'normal'. A diet change without a before-and-after measurement is almost always either underestimated (because improvement habituates quickly) or overestimated (because one good week feels like proof). Re-measuring every 3-6 months cleans out that noise.
What you can do yourself
Four things survive every meta-analysis: more vegetables and fruit (Aune et al. — each additional daily serving lowers mortality risk by about 5%),6 more fibre and whole grains, more unprocessed plant sources, and less ultra-processed food. The rest — keto, intermittent fasting, low-carb, plant-based — can work in specific contexts, but the net outcome almost always depends on those same four pillars.
The weakest hypothesis is that individual nutrients or supplements are the answer. With a few exceptions (vitamin D when deficient, omega-3 with low intake, B12 for vegetarians) the whole pattern delivers more than isolated pills.
When to involve a physician or dietitian
Book a GP or registered dietitian appointment for unexplained weight loss or gain, suspected eating disorders, food allergies or intolerances with clear symptoms, or chronic gut complaints. For tailored advice around blood markers (high apoB, prediabetes, iron deficiency), a blood test reviewed by a physician is the logical start. At Optimize our physician reviews every result and we reach out proactively when values warrant follow-up.