Recommended dietary intakes (RDIs)

Recommended dietary intakes (RDIs) are, perhaps, a good piece of evidence of how scientific knowledge has not yet being able to 'crack' fully the relationship between nutrient requirements and diet as for establishing balanced nutrition. At most, recommended dietary intakes are agreements reached by panels of experts, thus varying from country to country and, even, according to cultural background. Below are but a few of Western recommended dietary intakes, together with the more international recommendations made by WHO and FAO for the prevention of malnutrition and chronic disease, especially in poorer areas or the world.

WHO / FAO

The World Health Organization's standard for adults⁵ is as follows:

10-15% of energy intake from protein
15-30% of energy intake from fats (and no more than 10% of energy intake from saturated fats)
carbohydrate to provide the remaining energy intake by difference, thus, 55-75% of energy intake (and no more than 10% of energy intake from sugars)
25g or more of fiber
2600mg or less of sodium (the recommended intake for preventing high blood pressure was set at 1700mg or less)

USA / Canada

The United States and Canada's standard for adults³ ⁴ is as follows:

10-35% of energy intake from protein
20-35% of energy intake from fat (no limit for saturated fat was set⁷)
45-65% of energy intake from carbohydrate⁸ (and no more than 25% of energy intake from sugars)
38g or more of fiber for men, and 25g or more of fiber for women
2300mg or less of sodium (adequate intake was set at 1500mg)

Australia / New Zealand

The Australia and New Zealand's standard for adults⁶ is as follows:

15-25% of energy intake from protein
20-35% of energy intake from fat (no limit for saturated fat was set⁹)
45-65% of energy intake from carbohydrate (no limit for sugars was set⁹)
38g or more of fiber for men, and 28g or more of fiber for women
2300mg or less of sodium (adequate intake was set at 1600mg)

UK

The United Kingdom's standard for adults² ¹ is as follows:

No requirements for protein intake were set¹⁰
No more than 35% energy intake from fats¹¹ (and no more than 11% of energy intake from saturated fats)
50% of energy intake from carbohydrate (and no more than 11% of energy intake from sugars)
18g or more of fiber
2300mg or less of sodium (adequate intake was set at 1600mg)

References

1. COMMITTEE ON MEDICAL ASPECTS OF FOOD POLICY –COMA (1991). Dietary reference values (DRVs) for food energy and nutrients for the UK. Report on Health and Social Subjects 41, The Stationary Office, London (UK), 1991.

2. FOOD STANDARDS AGENCY (1991). FSA nutrient and food based guidelines for UK institutions. Food Standards Agency, October 2007, quoting the Committee on Medical Aspects of Food Policy –COMA (1991). Retrievable from FAS.

3. INSTITUTE OF MEDICINE OF THE NATIONAL ACADEMIES (2004). Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. The National Academies Press, Washington, D.C. (USA), 2005. ISBN: 0309091691. Also retrievable online from USDA.

4. INSTITUTE OF MEDICINE OF THE NATIONAL ACADEMIES (2005). Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. The National Academies Press, Washington, D.C. (USA), 2005. ISBN: 030908525X. Also retrievable online from USDA.

5. JOINT WHO/FAO EXPERT CONSULTATION (2002). Diet, nutrition and the prevention of chronic diseases. WHO Technical Report Series 916, Geneva (Switzerland), 2003. ISBN: 924120916X. Also retrievable online here.

6. NATIONAL HEALTH AND MEDICAL RESEARCH COUNCIL (AUSTRALIA) & MINISTRY OF HEALTH (NEW ZEALAND (2005). //Nutrient reference values for Australia and New Zealand. Executive summary. NHMRC, Australia, 2006. ISBN: 1864962496. Also retrievable online from NHMRC.

+++ Footnotes +++

7. This doesn't mean that saturated fats are of little concern for Americans, an example of which is the American Heart Association's drive to reduce the amount of saturated fats consumed to less than 7% of energy intake. Nonetheless, it seems reasonable to set upper limits of consumption for saturated fat in line with WHO's (at less than 10% of energy intake).

8. Notice that, if calculated by difference, then the recommended range of carbohydrate would be between 30-70% of energy intake, which is outside the recommended 45-65% range. It seems that a high protein (35%) - high fat (35%) diet is not recommended (as carbohydrate intake would be too low, at 30%). Equally, a low protein (10%) - low fat (20%) diet is not recommended either (as carbohydrate intake would be too high, at 70%). But both a high protein (35%) - low fat (20%) diet and a high fat (35%) - low protein (10%) diet fall within the adequate range.

9. This doesn't mean that saturated fats are of little concern for Australians and New Zealanders, an example of which is the National Heart Foundation's drive to reduce the amount of saturated fats consumed. Sugars, on the other hand, seem to draw less concern. Nonetheless, it seems reasonable to set upper limits of consumption for sugars and saturated fat in line with WHO's (at less than 10% of energy intake each).

10. Although the UK did not set protein requirements, it does not necessarily imply that they recommend a diet free of protein. We could calculate an approximate range of adequate protein intake by difference, after accounting for an adequate intake of fat and carbohydrate. Therefore we could assume that the UK would see adequate a diet providing between 15% and 35% of energy intake from protein.

11. It seems the UK was more concerned with setting an upper limit for fat than a lower one. This, however, does not necessarily imply that they recommend a diet free of fat. Thus, it seems reasonable to assume that at least the lowest value of recommended fat intake proposed by other standards may also be adequate for the UK diet. The lowest limit is that proposed by WHO, at 15% of energy intake. Therefore we could assume that the UK would see adequate a diet providing between 15% and 35% of energy intake from fat.

Want to know more?

Balanced nutrition: This Wiki of Science page deals with the meaning of balanced nutrition and how to differentiate it from related concepts, such as a balanced diet, a varied diet and a healthy diet.
The Balanced Nutrition Index™: A Wiki of Science page describes this nutritional technology used for estimating nutritional balance of foods, recipies and diets. But you can more information in the Balanced Nutrition Index™ database or the Balanced Nutrition Index™ journal.