Dietary Reference Intakes is the manual that explains what the diet experts' weasel words mean. These experts have done an excellent job of explaining in clear statistical terms what we really know about nutrition. Sure, it looks technical and plenty of grown ups will be put off by the math. I used to teach statistics, and there's nothing in here "No Child Left Behind" does not require of remedial 10th grade students.
It scares me how much diet advice Americans consume and how few people have read this book. "But it's free from the Government Printing Office!" you may say. Maybe, if you download it, but most people aren't going to spend the money to print this out and think about it. The paper version costs the same on Amazon as from the G.P.O., but Amazon ships for free and the GPO doesn't.
For each macronutrient (Protein, fat, fiber, carbohydrates) and for each micronutrient (the many vitamins and minerals) Dietary Reference Intakes explains how much we need and where we can get it. It explains differences by age and gender, and points out interactions that might make the obvious numbers differ from a specific situation. It gives more than one definition of "enough" for each nutrient.
EAR: Estimated Average Requirements (amounts half of the individuals need, most of the time),
RDA: Recommended Dietary Allowances (amounts almost all of the people in a group need, most of the time),
RDI: Recommended Dietary Intake (UnAmerican version of RDAs, so ask the Canadians),
AI: Adequate Intake (what average people really do, because nobody knows what they ought to need),
UI: tolerable Upper Intake levels (nobody should get more than this, but sadly many do)
EER: Estimated Energy Requirement (for calories), and
AMDR: Acceptable Macronutrient Distribution Ranges (for proteins, fats, and carbs)
Those of you who think the RDA amounts printed on the side of your vitamin bottle are strict and safe limits should read the section on the complexities of iron metabolism. Note that this is important, because iron deficiencies are the most widespread form of malnutrition in the world. Expertise doesn't produce definite answers. No one can give you a number that will protect you from all arguments.
Those of you who think there's nothing important in here need to take careful notes...
95% of American males and 75% of females get more then the tolerable upper limit of sodium and chloride.
Sugar should be limited to 25% of total carbohydrates. One can of Mountain Dew can exceed the daily limit.
Excellent science does not mean this is the final word on nutrition. The people who wrote this book recommend no more than minimal fats. Go read Gary Taubes' "Why Are We Fat" to understand why some serious scientists might disagree with even such a basic call.
There's an awful lot here to master. Reading it once will give you a general sense of the challenges of defining good nutrition. But Dietary Reference Intakes will leave you very much aware that there's way too much to keep in your head. To discuss these issues intelligently will take multiple readings. In the meantime, the book persuaded me take multiple vitamins.
Amazon reviews tend toward high rankings, so I've allowed some grade inflation...
==>6 stars - Buy this book now, you'll want it more than once ...if you're a pro
5 stars - Will reflect well on you if given as a gift
==> 4 stars - Worth reading to enrich your life ...for any American who gives or takes diet advice
3 stars - Entertainment for those with time on their hands
2 stars - Fun to read, but not the best use of time
1 star - So poorly written I felt like I wasted my time