Popular & commercial diet systems
Zone diet
Prescribes a fixed macronutrient ratio at every meal, roughly 40% carbohydrate, 30% protein, 30% fat, framed around controlling inflammation.
What people typically eat
Meals assembled to the 40-30-30 ratio: lean protein, low-glycaemic carbohydrates and monounsaturated fats, measured in "blocks".
What is restricted
High-glycaemic carbohydrates and meals that deviate from the ratio.
Why people try it
Structured eating with a performance and inflammation-control narrative.
Realistic advantages
- The resulting pattern, lean protein, vegetables, moderate carbs, is broadly sensible
- Regular meal structure suits people who like rules
- Emphasises unsaturated fats
Realistic disadvantages
- The block system is fiddly and time-consuming
- The precise 40-30-30 ratio has no demonstrated special benefit
- Anti-inflammatory claims exceed the evidence
Strength of evidence
Limited evidence
Studies of the specific ratio show no advantage over other calorie-matched diets; Mayo Clinic reviews rate it as roughly average.
Likely cost and difficulty
Moderate cost; high difficulty due to measuring.
Nutritional risks
Low; main cost is complexity.
Who should avoid it
No specific group.
Is professional supervision advisable?
Not required.
References
Written by the Slimr editorial team. How we review diets.
