One of the main reasons to avoid prepared foods is that they are loaded with sugar, which also disguised by other names such as fructose, agave nectar, high fructose corn syrup, dried cane juice (so what if it’s organic?), etc. Beyond diabetes, sugar may even promote heart disease and cancer!
However, I do eat lots of complex carbs, such as brown rice, sweet potatoes, and whole grain breads. (Note, most brown bread or “wheat” bread is NOT whole wheat!). Complex carbs raise your blood sugar slower and to a lesser extent than simple sugars (lower glycemic index).
I highly, highly recommend reading this article “Is Sugar Toxic” from the NY Times Magazine last month. Some quotes from it:
Having metabolic syndrome is another way of saying that the cells in your body are actively ignoring the action of the hormone insulin — a condition known technically as being insulin-resistant. Because insulin resistance and metabolic syndrome still get remarkably little attention in the press (certainly compared with cholesterol), let me explain the basics.
You secrete insulin in response to the foods you eat — particularly the carbohydrates — to keep blood sugar in control after a meal. When your cells are resistant to insulin, your body (your pancreas, to be precise) responds to rising blood sugar by pumping out more and more insulin. Eventually the pancreas can no longer keep up with the demand or it gives in to what diabetologists call “pancreatic exhaustion.” Now your blood sugar will rise out of control, and you’ve got diabetes.
… having chronically elevated insulin levels has harmful effects of its own — heart disease, for one. A result is higher triglyceride levels and blood pressure, lower levels of HDL cholesterol (the “good cholesterol”), further worsening the insulin resistance — this is metabolic syndrome…
If you want to cause insulin resistance in laboratory rats, says Gerald Reaven, the Stanford University diabetologist who did much of the pioneering work on the subject, feeding them diets that are mostly fructose is an easy way to do it. It’s a “very obvious, very dramatic” effect, Reaven says.
By the early 2000s, researchers studying fructose metabolism had established certain findings unambiguously and had well-established biochemical explanations for what was happening. Feed animals enough pure fructose or enough sugar, and their livers convert the fructose into fat — the saturated fatty acid, palmitate, to be precise, that supposedly gives us heart disease when we eat it, by raising LDL cholesterol. The fat accumulates in the liver, and insulin resistance and metabolic syndrome follow…
Michael Pagliassotti, a Colorado State University biochemist who did many of the relevant animal studies in the late 1990s, says these changes can happen in as little as a week if the animals are fed sugar or fructose in huge amounts — 60 or 70 percent of the calories in their diets. They can take several months if the animals are fed something closer to what humans (in America) actually consume — around 20 percent of the calories in their diet. Stop feeding them the sugar, in either case, and the fatty liver promptly goes away, and with it the insulin resistance.
The author then goes on to explain how the high levels of insulin and other growth factors in metabolic syndrome may promote the growth of cancer cells!
One observation is that death rates from cancer, like those from diabetes, increased significantly in the second half of the 19th century and the early decades of the 20th…The second observation was that malignant cancer, like diabetes, was a relatively rare disease in populations that didn’t eat Western diets, and in some of these populations it appeared to be virtually nonexistent…What these researchers call elevated insulin (or insulin-like growth factor) signaling appears to be a necessary step in many human cancers, particularly cancers like breast and colon cancer. Lewis Cantley, director of the Cancer Center at Beth Israel Deaconess Medical Center at Harvard Medical School, says that up to 80 percent of all human cancers are driven by either mutations or environmental factors that work to enhance or mimic the effect of insulin on the incipient tumor cells.
The standard disclaimer “more research is needed” applies. Still, I stopped drinking juice and eating pizza, and the pounds starting melting away! I don’t go hungry, either. And I don’t eat a low-carb diet.