Listening to an older NPR program - a couple of doctors trying to sell diet books - served as a reminder of why precisely my respect for the “nutritional community” seems to drop a notch every year. In part as over time I have gotten better at picking out a sharp (or not so sharp) mind out of a forest of words. Listening to the radio program, after mentally pruning out the excess verbiage - neither the “low-fat diet” doctor or the “low-carbohydrate” diet doctor impress me as anything near first-rate minds.
This is not surprising. I saw the weeding-out process applied to pre-med students while in college. What you largely get are folk able to grind forward in a single direction, without variation or creativity.
What this gets you is a large number of “studies” performed by guys with “doctor” in their title. When you look closely at the methodology of their study … you find stunning gaps. You very often find the “controlled study” is not at all well controlled (at least not by standards derived from studying Physics).
Back in high school did a lot of running (a 120 pound kid eating 11,000 calories a day), and after did a lot of cycling. Did long distance riding (30-70 miles a day) and events like one day 100 and 200 mile rides. Diet was absolutely crucial to success, and boiled down to the following observations as to which foods made the best fuels:
- Sugar is good only for a short-term boost - maybe 30 minutes. Good if you screwed up and let your blood sugar drop, and useless otherwise.
- Meat, fats, and oils digest too slowly and are not a good source when lots of energy is needed.
- Carbohydrates are your main fuel - crackers and bananas (washed down with copious water and some fruit juice) you can eat and burn while riding all day.
Afterwards, when much less physically active, it seemed logical to cut out the fuel - the carbohydrates - leaving mostly slow-burning foods (meat, fats and oils) in the diet. I had a hard time understanding why the “nutritional community” was recommending low-fat high-carbohydrate diets. It seemed counter-intuitive. Since your body tends to digest carbohydrates more quickly, you end up hungry between meals, which makes it harder to resist impulse eating.
Heard on NPR from a nurse who switched from the low-fat to low-carbohydrate diet: “ Carbohydrates made me hungry. “
Later I switched my diet to low in carbohydrate with most calories coming from lean meat and oils (olive, canola, etc.). I found with the slower to digest foods that I was not getting hungry between meals, and it was much easier to limit my intake.
You want my entirely non-professional dietary advice for typical minimally active suburbanites?
- Sugars are pure, absolute, unadulterated dietary evil - fruit sugars a bit less so. My bet is that we will eventually figure out that sugars killed more people than tobacco.
- Simple carbohydrates (white bread, white rice) are evil most days. Unless your day is going to be physically very active - stay away.
- Carbohydrates in general are fuel. If you are going to be active, you might eat more. Otherwise you want very little.
- Lean meat is good. Oils are generally good (fats liquid at room temperature). Fats solid at room temperature are probably bad.
- Salad with a bit of oil is good (small carbo with slow digesting oil).
… but I am not a “professional” …