Tag Archives: insulin

Is Insulin the Reason You’re Always Hungry?

So easy to over-eat!

So easy to over-eat! Is it the insulin release?

No, insulin probably isn’t the cause of constant hunger, according to Dr. Stephan Guyenet. Dr. G gives 11 points of evidence in support of his conclusion. Read them for yourself. Here are a few:

  • multiple brain-based mechanisms (including non-insulin hormones and neurotransmitters) probably have more influence on hunger than do the pure effect of insulin
  • weight loss reduces insulin levels, yet it gets harder to lose excess weight the more you lose
  • at least one clinical study (in 1996) in young healthy people found that foods with higher insulin responses were linked to greater satiety, not greater hunger
  • billions of people around the world eat high-carb diets yet remain thin

An oft-cited explanation for the success of low-carbohydrate diets involves insulin, specifically the lower insulin levels and reduced insulin resistance seen in low-carb dieters. They often report less trouble with hunger than other dieters.

Here’s the theory. When we eat carbohydrates, the pancreas releases insulin into the bloodstream to keep blood sugar levels from rising too high as we digest the carbohydrates. Insulin drives the bloodstream sugar (glucose) into cells to be used as energy or stored as fat or glycogen. High doses of refined sugars and starches over-stimulate the production of insulin, so blood sugar falls too much, over-shootinging the mark, leading to hypoglycemia, an undeniably strong appetite stimulant. So you go back for more carbohydrate to relieve the hunger induced by low blood sugar. That leads to overeating and weight gain.

Read Dr. Guyenet’s post for reasons why he thinks this explanation of constant or recurring bothersome hunger is wrong or too simplistic. I tend to agree with him on this.

The insulin-hypoglycemia-hunger theory may indeed be at play in a few folks. Twenty ears ago, it was popular to call this “reactive hypoglycemia.” For unclear reasons, I don’t see it that often now. It was always hard to document that hypoglycemia unless it appeared on a glucose tolerance test.

Regardless of the underlying explanation, low-carb diets undoubtedly are very effective in many folks. That’s why I offer one as an option in my Advanced Mediterranean Diet. And low-carbing is what I always recommend to my patients with carbohydrate intolerance: diabetics and prediabetics.

Steve Parker, M.D.

front cover

front cover

Steve Parker MD, Advanced Mediterranean Diet

Two diet books in one

front cover

front cover

Prolonged Sitting Is the New Trans Fat: Avoid It

Within the last couple months I read somewhere that the adverse health effects of sitting all day long are not counteracted by an hour of vigorous exercise.  If true, that’s disappointing to many of us.

I think this is the research report that got the buzz going.

The investigators suggest you’re better off with four hours of standing and two hours of walking.  Easy peasy, right?

Some caveats.  It’s a very short-term small study of young adults (18 initially but three dropped out).  The “prolonged sitting” regime lasted 14 hours.   The health focus of the study was limited to insulin levels, insulin sensitivity, blood sugar levels, and blood lipids like cholesterol and triglycerides.

Where did I read, “Sitting is the new saturated fat”?

The investigators conclude…

One hour of daily physical exercise cannot compensate the negative effects of inactivity on insulin level and plasma lipids if the rest of the day is spent sitting. Reducing inactivity by increasing the time spent walking/standing is more effective than one hour of physical exercise, when energy expenditure is kept constant.

The Washington Post in July, 2011, had an article along the same lines (h/t Beth Mazur).

—Steve Parker, M.D.

Reference:  Duvivier BMFM, Schaper NC, Bremers MA, van Crombrugge G, Menheere PPCA, et al. (2013) Minimal Intensity Physical Activity (Standing and Walking) of Longer Duration Improves Insulin Action and Plasma Lipids More than Shorter Periods of Moderate to Vigorous Exercise (Cycling) in Sedentary Subjects When Energy Expenditure Is Comparable. PLoS ONE 8(2): e55542. doi:10.1371/journal.pone.0055542

Prostate Cancer Deaths Linked to Overweight and High Insulin Levels

Lancet Oncology in 2008 published a report associating worse prostate cancer outcomes—death, that is—with overweight, obesity, and hyperinsulinemia.

Grapes are an iconic Mediterranean fruit

Researchers looked at data from the respected Physicians’ Health Study, finding 2,546 men who developed prostate cancer during many years of observation. Of these men, 38.8% were overweight (body mass index 25–30) and 3.4% were obese (BMI over 30).

(For definitions of overweight and obesity, and to calculate your body mass index, click here.)

Compared with normal-weight men (BMI under 25) who developed prostate cancer, overweight men with prostate cancer were one-and-a-half times more likely to die from the cancer. Obese men with prostate cancer were two-and-a-half times more likely to die.

A blood test called C-peptide is a marker of insulin resistance and hyperinsulinemia. Obesity is often accompanied by high insulin levels and insulin resistance. Overweight, not so much. Eight hundred twenty-seven of the men with prostate cancer had C-peptide levels drawn at baseline, before diagnosed with cancer. Men with the highest C-peptide levels were almost two-and-a-half times more likely to die of prostate cancer than men with the lowest C-peptide levels.

Study participants having both excess body weight and high C-peptide levels had the worst outcome.

Prostate cancer is the most common invasive cancer in U.S. men, with about 185,000 cases diagnosed every year. It is one of the cancers that can be prevented by following the traditional Mediterranean diet for years. The other prevented cancers are breast, uterus, and colorectal. Obesity predisposes men to cancer of the prostate, colon, rectum, kidney, and esophagus.

The study at hand suggests that if you are overweight or obese and then develop prostate cancer, you have a greater risk of dying from the cancer compared with healthy-weight men. Given that prostate cancer is so common, why not cut your risk of getting it and dying from it by controlling your weight with a Mediterranean-style diet?

Steve Parker, M.D.

Reference: Ma, Jing, et al. Prediagnostic body mass index, plasma C-peptide concentration, and prostate cancer-specific mortality in men with prostate cancer: a long-term survival analysis. Lancet Oncology, online publication October 6, 2008. DOI: 10.1016/S1470-2045(08)70235-3

Competing Theories of Overweight and Obesity

God, help us figure this out

A few months ago, several of the bloggers/writers I follow were involved in an online debate about two competing theories that attempt to explain the current epidemic of overweight and obesity. The theories:

  1. Carboydrate/Insulin (as argued by Gary Taubes)
  2. Food Reward (as argued by Stephan Guyenet)

The whole dustup was about as interesting to me as debating how may angels can dance on the head of pin.

Regular readers here know I’m an advocate of the Carboydrate/Insulin theory. I cite it in Conquer Diabetes and Prediabetes: The Low-Carb Mediterranean Diet and The Advanced Mediterranean Diet: Lose Weight, Feel Better, Live Longer (2nd edition). But the Food Reward theory also has validity. They’re both right, to an extent. They’re not mutually exclusive. The Food Reward theory isn’t as well publiziced as Carbohydrate/Insulin.

Dr. Guyenet lays out a masterful defense of the Food Reward theory at his blog. Mr. Taubes presents his side here, here, here, here, and here. If you have a couple hours to wade through this, I guess I’d start with Taubes’ posts in the order I list them. Finish with Guyenet.

You’d think I’d be more interested in this. I’m still not.

Moving from theory to real world practicality, I do see that limiting consumption of concentrated refined sugars and starches helps with loss of excess body fat and prevention of weight regain. Not for everbody, but many. Whether that’s mediated through lower insulin action or through lower food reward, I don’t care so much.

Steve Parker, M.D.

h/t Dr. Emily Deans