A low-carb diet is healthful in Japan too


Many studies demonstrate the advantages of a low-carb diet for weight loss without hunger, and for blood-sugar control in type 2 diabetes. Now there’s also a new Japanese study showing the same thing.

I was going to write about it, but Dr. Anders Tengblad beat me to it:

DiabetesDoc: Low-Carb in Japan [Update 2019: No longer online]

Excerpt from Dr. Tengblad’s post:

The study monitored calorie intake and discovered that despite that the subjects in the low-carb group were not calorie-restricted, they still didn’t consume more calories. The authors also calculated correlations between changes in calories and changes in the amount of carbohydrate, and found that the amount of calories was associated with weight change, while the amount of carbohydrate was associated with blood sugar control. Thus, a low-carb diet is not just a weight-loss diet, but independently of weight, also a way to control blood sugar. Obvious, you might think. But it still has to be established.

A third interesting aspect is that the authors made an effort to study the potential impact of changes in diet on arteries. Among other things, they measured arterial stiffness, which i something that’s been speculated to be negatively impacted by a high-fat diet. In the Japanese study, no adverse effects from a low-carb diet were observed. The authors conclude, as many previous studies have, that a low-carbohydrate diet is effective and safe.

I wonder what they did about the rice, but the article doesn’t say.

This was a fairly small study, and the results are not new. It’s been shown many times that a low-carb diet improves blood sugar control and lipid profile, especially triglyceride levels, and it’s interesting to see that more and more countries rediscover the old diabetes diet.


Diabetes – How to Normalize Your Blood Sugar

LCHF for Beginners

New Study: A Low-Carb Diet and Intermittent Fasting Beneficial for Diabetics!

One Year on an LCHF Diet with Type 1 Diabetes

“Hello LCHF – Goodbye Type 2 Diabetes”


  1. Wade Henderson
    While I don't have any doubt they lower their weight on such a diet, I can't help but look at the diet of the overall Japanese population and their incidence of Type 2 diabetes.

    Looking at the IDF Diabetes Atlas 6th edition, Belgium 2013, I see the following for men and women between the ages of 20 and 79

    Japan 5.12%
    Sweden 4.69%
    USA 9.21%

    It would seem that the general Japanese population doe fairly well on a diet that includes a great deal of rice, etc.
    Having said that, the subset that gains excess weight and becomes prone to Type 2 diabetes would no doubt do well and lose weight on the diet shown in the study.

    Not sure it says anything about the general Japanese diet.

    Ukraine has only a 2.45% incidence while Saudi Arabia is at 23.87%
    Interesting. Wonder if all the reporting is valid.


  2. Damocles
    A general thing about the Japanese diet:

    they consume much more unsweetened beverages (in particular green tea, and unsweetened green ice-tea) instead of sweetened softdrinks.
    Also having more cocked dishes from ingrediences you can still recognize, instead of supermarket ready-meals.

    At least that was my observation during my trip to Japan.

  3. Jack
    What is interesting is that this study was funded by Glico (large processed food company), Lawson (major convenience store in Japan selling 99% processed junk), and Kirin (beer brewer).

    Imagine Coca Cola, Nestle and Unilever funding a study in the US which shows that low carb diets have a positive effect on diabetes.

    And yes, when they say low carb they mean rice and bread as well.

    Here's an article (in Japanese) from the Nikkei newspaper on the study:


  4. charles grashow

    1) It wasn't really low carb

    For the low-carbohydrate diet, we set the total carbohydrate intake to be <130 g/day, as proposed by Accurso et al. (15). To prevent ketosis (11, 12, 16), we set the lower limit of carbohydrate intake to 70 g/day. To prevent postprandial hyperglycaemia, the target carbohydrate content in each meal was 20-40 g, and the subjects were allowed to consume sweets containing 5g of carbohydrates twice daily, thus resulting in a total carbohydrate intake of 70-130 g/day.

    The relative nutrient intake of carbohydrates, protein and fat was 29.8±12.5%, 25.3±7.3% and 45.4±8.9% in the low-carbohydrate group.

    2) The study doesn't state what either group ate.

    3) The HbA1C levels were staring to increase for the low carb group after 4 months

  5. Jack
    Low carb and ketosis are not the same thing.

    And according to the Nikkei article I linked to what is a "carb restricted diet" in Japan is one where rice and bread intake are reduced.

  6. Jack
    Correct link to the Japanese Nikkei article:


  7. Marc
    The Japanese eat rice but unlike many westerners they fully understand that it is fattening. When Japanese people start to get chunky they know to cut back on the rice. They dont think it is a health food.

    They also have a taste for fat and prefer very fatty cuts of meat. Fish is a big part of their diets as well as an enormous amount of green tea. They also eat much less sugar then we do.

  8. François
    Interesting article... This proves that even a partial decrease of carbohydrates has a significant positive effect on type 2 diabetes, even though the positive effect is only temporary, as per this article, clearly 135 grams of carbohydrates is still too much for someone with type 2 diabetes (HbA1C increases again after 4 months).
    It is sad so many people do not make the difference between nutritional ketosis and diabetic keto-acidosis. It is even more sad that the diabetes associations do not recommend a true low carb diet because "no long term study has shown the efficacy effects of such a diet or whether or not it could have potential side effects".
    Dr Jason Fung, a Canadian nephrologist, has cured with a true low carb diet and by having his patients skip breakfast nearly every case of diabetes he has treated. By curing I mean stopping medication and reducing insulin levels while obtaining normal glucose levels. I do not mean enabling people to eat as many carbs as they want - this is totally different. He has a great presentation on Youtube.
    So in order to be "on the safe side", diabetic associations recommend that patients with diabetes eat a "safe and healthy" level of carbs to which they are intolerant, despite the fact that all long term studies have shown that by increasing insulin, diabetes gets worse and people's risk of disease is greatly increased. I guess they are garanteed a "safe stroke", a "safe heart and vascular disease", a "safe kidney failure" and a "safe retinopathy and neuropathy". Sad people listen to these "experts"

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