Why Low Carb?

OmniCarb (Sacks et al., 2014)

Study design & results in a nutshell:

5 weeks, low(ish) vs. high carb (40 vs. 58%) with the calorie difference split between protein (23 vs. 16%) and fat (37 vs. 27%).  In other words, the low(ish) carb diet was higher in protein and fat.  And there was 2 versions of each diet —  a high and low glycemic index.  Lots of crossing over; all in all, weak intervention but decent study design & execution.

Aaaand nothing drastic happened.  Goal was insulin sensitivity, not weight loss.


glucose and insulin


Important points:

1) The participants were relatively healthy at baseline.  Anyone on meds was excluded.  Average BMI 32.  Mostly educated non-smokers.  This population is expected to respond reasonably well to any diet (wrt body weight… see next point).

2) “Calorie intake was adjusted to maintain initial body weight.”

^^^this really knocks the wind out of low carb. One of the big benefits of cutting carbs is spontaneous appetite suppression –- two points here: 1) this effect is most prominent in obese IR; and 2) it is more relevant to weight loss.  By not targeting insulin resistant and/or type 2 diabetics, and feeding specifically to prevent weight loss, I ask you this: Why Low Carb?

3) the biggest difference between the two diets was carbs (45% higher in low[ish] fat group), but the biggest difference from baseline, was protein in the LC group (53% increase).  In other words, the Low Carb group had their carbs decreased from 50 to 40% of calories. *meh*

4) Body composition wasn’t assessed; so even if LCHP induced nutrient partitioning and improved body comp, we wouldn’t know it.

5) Everyone was eating cereal or oatmeal for breakfast, bread with most meals, and pasta or rice for dinner.  What did you expect?  Really?


Prior posts in what seems to be developing into a series of rants:
2 New Diet Studies
CICO and rant 


calories proper

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  • Tuck

    LOL. 40% carbs…

  • Kindke

    There is a typo in his name actually its “sucks et al, 2014″

    • This Old Housewife

      Agreed. The effort was so small–why did they even bother?

  • Bill Lagakos

    A lower-carbohydrate, higher-fat diet reduces abdominal and intermuscular fat and increases insulin sensitivityin adults at risk of type 2 diabetes.

    Obesity, particularly visceral and ectopic adiposity, increases the risk of type 2 diabetes. The aim of this study was to determine if restriction of dietary carbohydrate is beneficial for body composition and metabolic health. Two studies were conducted. In the first, 69 overweight/obese men and women, 53% of whom were European American (EA) and 47% of whom were African American (AA), were provided with 1 of 2 diets (lower-fat diet: 55%, 18%, and 27% of energy from carbohydrate, protein, andfat, respectively; lower-carbohydrate diet: 43%, 18%, and 39%, respectively) for 8 wk at a eucaloric level and 8 wk at a hypocaloric level. In the second study, 30 women with polycystic ovary syndrome (PCOS) were provided with 2 diets (lower-fat diet: 55%, 18%, and 27% of energy from carbohydrate, protein, and fat, respectively; lower-carbohydrate diet: 41%, 19%, and 40%, respectively) at a eucaloric level for 8 wk in a random-order crossover design. As previously reported, among overweight/obese adults, after the eucaloric phase, participants who consumed the lower-carbohydrate vs. the lower-fat diet lost more intra-abdominal adipose tissue (IAAT) (11 ± 3% vs. 1 ± 3%; P < 0.05). After weight loss, participants who consumed thelower-carbohydrate diet had 4.4% less total fat mass. Original to this report, across the entire 16-wk study, AAs lost more fat mass with a lower-carbohydrate diet (6.2 vs. 2.9 kg; P < 0.01), whereas EAs showed no difference between diets. As previously reported, among women with PCOS, thelower-carbohydrate arm showed decreased fasting insulin (-2.8 ?IU/mL; P < 0.001) and fasting glucose (-4.7 mg/dL; P < 0.01) and increased insulinsensitivity (1.06 arbitrary units; P < 0.05) and "dynamic" ?-cell response (96.1 · 10(9); P < 0.001). In the lower-carbohydrate arm, women lost both IAAT (-4.8 cm(2); P < 0.01) and intermuscular fat (-1.2 cm(2); P < 0.01). In the lower-fat arm, women lost lean mass (-0.6 kg; P < 0.05). Original to this report, after the lower-carbohydrate arm, the change in IAAT was positively associated with the change in tumor necrosis factor ? (P < 0.05).


    A modest reduction in dietary carbohydrate has beneficial effects on body composition, fat distribution, and glucose metabolism.

  • Phil Thompson

    The low GI approach appears to be a bad idea – “At high dietary carbohydrate content, the low- compared with high-glycemic index level decreased insulin sensitivity from 8.9 to 7.1 units (-20%, P?=?.002); increased LDL cholesterol from 139 to 147 mg/dL (6%, P???.001); and did not affect levels of HDL cholesterol, triglycerides, or blood pressure.”

    We don’t want Type 2 diabetics eating low GI and reducing their insulin sensitivity.

    • Bill Lagakos

      “We don’t want Type 2 diabetics eating low GI and reducing their insulin sensitivity.”

      I’d rather see carbs lower than 40% in this population…

  • Santino Corleone

    Was your question about “if not looking for weigjt loss ir insulin sensivity…why low carb?” serious?

    I live ketogenic because of blood sugar stabilization (–> mood stabilization for bipolar)

    I am more stable but I miss some carbs like rice or sweet potatoes etc…

    I am lean (8% body fat before keto diet) and until now I gained 3 kg and now have 10,5% body fat. This happened within 2 months.

    I hope I won’t gain much more fat…

    Do you think it is harmful to stay low carb to long if bot adressing insuline sensivity or overweight?

    Best regrds

    • Bill Lagakos

      “Was your question about ‘if not looking for weight loss ir insulin sensivity…why low carb?’ serious?”

      Somewhat, tongue-in-cheek…

      According to most studies, the population who serves to benefit most from Low Carb is obese insulin resistant; and the result being weight loss — by excluding these people and not focusing on weight loss, then the results won’t be as robust.

      “Do you think it is harmful to stay low carb too long…”

      No. There is no evidence that Low Carb is harmful, for any duration.

  • Yaroslav Fedevych

    Is there any good study, or at least a well-informed article on the longer-terms effects of low carb for those who are already type 2 diabetic? I see a lot of “preventing risk for those in pre-diabetes and insulin resistant”, but rather little to none in-depth information about those who are already there, and little to none information on what does augment any positive effect.

    Every doctor I’ve seen so far in my locality advised me to go low-fat (which helped nothing in terms of blood glucose levels, and drained the joy of eating rather severely; low-carb makes the BG control easy as a pie, but what else would it do with regard to my remaining beta cells and insulin sensitivity, I’ve yet to see…).

    Sincerely, an obese type 2 diabetic guy.

  • Marcos Taquechel

    The other
    day I stumbled into this an youtube ( a video in
    favor of high carb diet for diabetes. I became puzzled with a question I could not answer. A study saying that red meat raises insulin levels quite a lot. Thestudy (quite old)

    The only think I know is that there is no glucose spike involved. Why there is insulin spike with meat? What happens to that insulin? Does insulin from meat consumption behaves the same as any other insulin spike? Does it promote other
    metabolic changes since there is no glucose involved?