Breakfast and BG levels
What goes around, comes around. Or something like that. I’ve never been good with popular sayings.
But trends in nutrition, especially nutrition for people with diabetes, seem to go in cycles. At the beginning of the 20th century, low-carb was the dogma for people with diabetes. Then after the 1950s it slowly switched to high-carb, low-fat. Now many people are returning to the low-carb approach.
But with each swing in trends, much old knowledge is lost, and scientists seem to reinvent the wheel. This is illustrated in some of the Adele Davis books. For those not familiar with her, she was a health food writer popular in the 1960s and 1970s, before the low-fat mania took over the country. I was looking at “Let’s Eat Right to Keep Fit,” which was originally published in 1954 and updated in 1970, because I was curious about what nutritional advice was 40 or so years ago.
Interestingly, even back then she was telling people to avoid hydrogenated fats and pointing out that peanut butter, which used to be considered healthy, was healthy no longer because of the hydrogenation. Hydrogenating fat is what causes trans fats, which are now considered health risks.
But even more interesting is a section discussing breakfast options. This is based on a 1949 USDA circular (No. 827) entitled “The Breakfast Meal in Relation to Blood Sugar values.” I’d like to read it, but I can’t seem to find access to it anywhere. It’s the sort of pamphlet that people throw away because they figure it’s outdated information.
One interesting thing in the discussion of this research is that Davis seemed to be more concerned with low blood sugar than with high. Her idea of a good breakfast was one that raised blood glucose (BG) levels to 120 and kept them there all morning.
Yet low-carb gurus like Dr. Richard Bernstein say that our BG should stay at about 83 all day long, even after meals. Many people with diabetes feel that Bernstein’s standards are a bit too strict, and many people without diabetes go over 120 after meals, but they then return to lower levels in the 80s or 90s in a short time.
In the experiments cited by Davis, 200 volunteers ate different breakfasts and their BG level was measured before the meal and hourly for 3 hours afterward.
After black coffee alone, their BG levels dropped and they had symptoms of hunger, fatigue, nervousness, irritability, exhaustion, lassitude, and headaches (which I’ll just call “low BG symptoms” henceforth) that got worse as the morning progressed. (For years I had only black coffee for breakfast, and I never got hungry or had headaches. If I occasionally had breakfast, that would make me hungry long before lunch.)
Two doughnuts and coffee with cream resulted in a rapid increase in BG, but it fell within an hour to “a low level” (not specified) with low BG symptoms.
They selected a “basic breakfast” that they thought was representative of the typical American breakfast: orange juice, 2 strips of bacon, toast, jam, and coffee with cream and sugar. This caused the BG to increase rapidly, but it fell below the prebreakfast level within an hour and remained below normal until lunchtime. Adding packaged cereal to the basic breakfast had the same result.
When they added oatmeal with sugar and milk to the basic breakfast, the BG rose rapidly but fell more quickly and to a lower level than any other breakfast studied. This is really odd, as oatmeal is relatively low glycemic and is supposed to slow digestion down. Perhaps they overdid the added sugar.
When they added 8 ounces of whole milk fortified with 2.5 tablespoons of powdered skim milk, on the other hand, BG levels rose and stayed at 120 mg “throughout the morning,” which presumably meant for the 3 hours that they measured, and “unusual well-being was reported.”
Then they added two eggs instead of the fortified milk and “again a high level of efficiency was maintained,” where “a high level of efficiency” probably means higher BG levels throughout the morning, accompanied by a lack of low BG symptoms. Finally, they added both eggs or fortified milk and larger amounts of toast and jam and again found that “efficiency stayed high.”
Basically, what they found was that people felt better when they had protein for breakfast. Without it, BG levels went up and then quickly dropped down below the starting levels, making people feel tired and irritable.
They then gave the volunteers lunch (cream cheese on whole-wheat bread and a glass of whole milk; anathema to today’s nutritionists). In all cases, BG levels went up, but people who had eaten eggs or fortified milk for breakfast “showed a high blood sugar all afternoon.” By “high” I’m sure that Davis meant “non-low.”
Then she notes that a similar finding had been published in 1943 in the Annals of Internal Medicine: “A comparison of the metabolic effects of isocaloric meals of varying composition with special reference to the prevention of postprandial hypoglycemic symptoms.”
In the earlier study, a high-carb meal consisting of orange juice, bacon, jelly, packaged cereal and coffee, both with sugar and milk, made BG levels rise quickly but then fall, causing “fatigue and inefficiency.” Packaged cereal eaten with only whipping cream made BG levels increase slightly and then remain at fasting levels all morning. A high-protein meal of skim milk, lean ground beef, and cottage cheese made the BG level go up to 120 and stay there for the next six hours.
Note that the 200 volunteers were not known to be diabetic, although some of them might test diabetic with the stricter standards of today. She said that normal fasting BG levels are 80 to 120 mg/dL, the latter now considered to be prediabetic.
But what is interesting is that it has been known since the 1940s that high-carb breakfasts cause BG problems, and yet that’s what so many dieticians are telling people to eat today.
If a nondiabetic volunteer’s BG went “high” and then plummeted, you can imagine what would happen to someone with diabetes. Many people diagnosed with type 2 diabetes report such “reactive hypoglycemia,” or going low after high-carb, low-protein meals. It used to happen to me as long ago as the 1970s when I ate only carbohydrate for breakfast.
When the same thing happens to nondiabetics and they get hungry midmorning, they’re apt to go to the candy machine to bring their BG levels up. That’s what I used to do. This would make the BG shoot up again and then plummet again. More hunger. More candy. And eating candy between meals is not a great way to keep your weight under control.
What’s sad is that this knowledge seemed to have been lost during the low-fat, high-carbohydrate diet craze of the past few decades. Because the older articles are not online, people can’t find them unless they go to academic libraries that keep copies of old journals. And even then, they’re not apt to look because they may consider old research useless today.
Davis describes the high-protein farm breakfasts of her Indiana youth: “hot cereal, steaks, ham and/or eggs, huge patties of sausage or fried chicken with country gravy; a large pitcher of [undoubtedly whole] milk was regularly on the table.”
I wouldn’t recommend eating such huge breakfasts unless you’re planning to go out and cut some hay with a scythe. But it’s certainly time to stop the insanity of all-carbohydrate breakfasts both for people with diabetes and for those without.
Current research confirms this old research and presents it in a more graphic way. These researchers showed huge BG increases when nondiabetics ate high-carbohydrate breakfasts.
It’s time to return to the higher-protein breakfasts of the past.
Gretchen wrote for HealthCentral as a patient expert for Diabetes.