On a high-carb diet, people with diabetes need less insulin

The more car­bo­hy­drate you eat, the more respon­sive your body becomes to the hor­mone insulin. That is why high-car­bo­hy­drate diets cure type 2 dia­betes. They also reduce insulin require­ments in peo­ple with type 1 dia­betes. If you are tak­ing insulin, talk to your doc­tor before you switch to a high-car­bo­hy­drate diet. Oth­er­wise, you could end up with a dan­ger­ous bout of low blood sug­ar.

Behind Barbed Wire_PrintAs I explain in my book Thin Dia­betes, Fat Dia­betes: Pre­vent Type 1, Cure Type 2, There are two main type of sug­ar dia­betes (dia­betes mel­li­tus). If you have thin dia­betes (type 1 dia­betes mel­li­tus), your pan­creas can­not make enough insulin to keep you alive. If you have fat dia­betes (type 2 dia­betes mel­li­tus), your body is resist­ing the effects of insulin, to keep you from stor­ing more fat in your fat cells. You can have both prob­lems at once. In oth­er words, even peo­ple with insulin short­age can have some degree of insulin resis­tance.

The solu­tion to insulin resis­tance has been known since the 1930s: eat a high-carb, low-fat diet. The more carbs you eat, the more sen­si­tive your body becomes to insulin. The more fat you eat, the more resis­tant your body becomes to insulin. When peo­ple with type 1 dia­betes start a high-carb diet (>75% of calo­ries in the form of car­bo­hy­drate), they often have to decrease their insulin dosage by about 30%.


2 thoughts on “On a high-carb diet, people with diabetes need less insulin”

  1. This is 100% false. The more carbs the more insulin you need. I’m type 1 and you should delete this mis­in­for­ma­tion if you have any self respect.

    1. Hi Jeff:
      I have spent 30 years edit­ing med­ical text­books, includ­ing nutri­tion text­books, and med­ical jour­nal arti­cles. Before the dis­cov­ery of insulin, the only way to man­age type 1 dia­betes was to feed a near-star­va­tion diet that was extreme­ly low in car­bo­hy­drate. After the dis­cov­ery of insulin, doc­tors at first thought that peo­ple with dia­betes need­ed to eat low-carb diets. Yet by 1927, it was becom­ing obvi­ous that insulin-treat­ed patients with type 1 dia­betes were doing bet­ter on high-car­bo­hy­drate, low-fat diets. In the 1930s, Dr. H. P. Himsworth did some impor­tant stud­ies that showed that the high blood sug­ar in peo­ple with type 2 dia­betes was due to insulin resis­tance, and that this insulin resis­tance could be cre­at­ed in a healthy per­son by feed­ing him a high-fat (80% fat by calo­rie) diet for only a week. As Himsworth replaced the fat in the test diet with starch, his sub­jects’ glu­cose tol­er­ance (as indi­cat­ed by the results of a glu­cose tol­er­ance test) improved dra­mat­i­cal­ly. The test sub­jects (again, these were healthy vol­un­teers) had the most sta­ble blood sug­ar after hav­ing eat­en a high-carb test diet (80% car­bo­hy­drate by calo­rie) for a week. Dur­ing the 1930s and 1940s, Dr. Wal­ter Kemp­n­er began exper­i­ment­ing with an extreme­ly high-car­bo­hy­drate diet for patients who had severe high blood pres­sure. He told his patients to eat noth­ing but white rice (Uncle Ben’s Con­vert­ed Rice), fruit, and fruit juice. To reduce the pro­tein con­tent even more for patients with real­ly severe kid­ney dis­ease, he rec­om­mend­ed that some of the rice be replaced with pure white sug­ar. This diet had such remark­able effects on the health of the cir­cu­la­to­ry sys­tem that Kemp­n­er was accused of fak­ing his results. When Kemp­n­er start­ed rec­om­mend­ing this diet to patients with dia­betes, he found that it cured “mild” dia­betes (what is now called type 2) and reduced the insulin require­ments for patients with “severe” dia­betes (type 1). Like­wise, Dr. John McDougall has found that he often has to cut the insulin dosages for his patients with type 1 dia­betes by about 30% after they start eat­ing the extreme­ly high-car­bo­hy­drate diet that he rec­om­mends.

      The rela­tion­ship between diet, insulin dosages, and blood sug­ar is con­fus­ing until you under­stand what insulin real­ly does. Insulin is not an anti­dote to sug­ar. It is actu­al­ly the hor­mone that switch­es the cells through­out your body from the fast­ing state to the fed state. Insulin encour­ages the liv­er to store a lot of the incom­ing sug­ar from a meal as a starch called glyco­gen. As a result of this effect of insulin on the liv­er, a lot of the sug­ar that is being absorbed from the food does not reach the gen­er­al cir­cu­la­tion. That is why healthy peo­ple on high-car­bo­hy­drate diets have a very small blood glu­cose spike even after they have eat­en a high-car­bo­hy­drate meal. Insulin also trig­gers the expres­sion of GLUT4 glu­cose trans­porters on heart and mus­cle cells. As a result, insulin allows the heart and mus­cles to use more glu­cose for ener­gy. (You can also increase the expres­sion of those GLUT4 trans­porters by exer­cis­ing. That’s why exer­cise has been called the invis­i­ble insulin.) How­ev­er, insulin also tells cells what to do with amino acids (the build­ing blocks of pro­tein) and fats. Insulin tells the fat cells to store fat right away. So under the influ­ence of insulin, you store fat and burn sug­ar. Insulin also encour­ages cells to take in amino acids and use them for build­ing pro­teins. In oth­er words, insulin is an ana­bol­ic (growth) hor­mone. By telling your liv­er to store sug­ar and your heart and mus­cles to burn sug­ar, insulin decreas­es blood sug­ar lev­els. How­ev­er, insulin’s most pow­er­ful (and most dan­ger­ous) effect on blood sug­ar comes through its effect with­in the pan­creas. Insulin sup­press­es the release of glucagon, which is the anti-insulin. I men­tioned that insulin is the hor­mone that allows your body to cope with a meal. Glucagon is the hor­mone that allows your body to sur­vive a fast. Glucagon is a cata­bol­ic hor­mone, which means that it pro­motes break­down of tis­sue. Glucagon tells the liv­er to turn some of its stored glyco­gen back to glu­cose, to keep blood sug­ar lev­els from drop­ping to a dan­ger­ous­ly low lev­el. That explains why insulin over­dose can cause death from hypo­glycemia, as well as why glucagon is used as an anti­dote to insulin over­dose.

      Insulin is a hor­mone, and its effect on the body can in turn be reg­u­lat­ed by oth­er things. One is body weight, and anoth­er is the diet that you have been eat­ing for the past week or so. If the body judges that it has already stored enough fat, it may start to resist the effects of insulin, to pre­vent fur­ther weight gain. If the per­son keeps gain­ing weight any­way, the insulin resis­tance can get so severe that the body los­es con­trol over its blood sug­ar. This is the under­ly­ing prob­lem in type 2 dia­betes. That is why weight loss of any cause revers­es type 2 dia­betes. The body can also resist the effects of insulin if the diet is high in fat. That’s why Himsworth was able to cause abnor­mal glu­cose tol­er­ance in healthy sub­jects by feed­ing them a high-fat diet for a week, and why his test sub­jects had remark­ably sta­ble blood glu­cose lev­els dur­ing the glu­cose tol­er­ance test after they had eat­en a high-car­bo­hy­drate diet for a week.

      The take-home mes­sage is this: An extreme­ly high-car­bo­hy­drate, low-fat diet based on whole plant foods is the best diet for pro­mot­ing the long-term healthy sur­vival of peo­ple with type 1 dia­betes. Not only does it pro­mote more sta­ble blood sug­ar, it helps to pro­tect against the cir­cu­la­to­ry dis­eases that are such impor­tant caus­es of death and dis­abil­i­ty in peo­ple with type 1 dia­betes. How­ev­er, and this is impor­tant, a switch to a very high-car­bo­hy­drate diet (80% or more by calo­rie) will cause your body to become much more sen­si­tive to insulin. As a result, you will prob­a­bly need to reduce your insulin dosage. This change may take a week or more, so you would need to mon­i­tor your blood sug­ar care­ful­ly and be on the look­out for hypo­glycemia.

      I explain all this in detail in my book Thin Dia­betes, Fat Dia­betes: Pre­vent Type 1, Cure Type 2 (http://www.thindiabetes.com)

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