Louise A McKenna academic foundation year 1 doctor, Russell S Drummond consultant endocrinologist, Suzannah Drummond consultant ophthalmologist, Dinesh Talwar consultant biochemist, Michael EJ Lean professor of human nutrition and consultant physician
McKenna L A, Drummond R S, Drummond S, Talwar D, Lean M E.
Seeing double: the low carb diet
BMJ 2013; 346 :f2563
doi:10.1136/bmj.f2563
Re: Seeing double: the low carb diet
I agree with the previous respondent on the misleading title. This is not primarily about Low Carbohydrate Diets and erroneously infers that Low Carb puts you at risk of thiamine deficiency. Admittedly whole grains are a source of thiamine, as are refined grains by dint of fortification due to losses in processing. Other foods high in thiamine are legumes, nuts, seeds (especially sunflower), pork, organ meats and Marmite.
Thiamine is linked with metabolism of carbohydrates. Weak evidence suggests increases in carb intake as a percentage of caloric intake increase the requirement of thiamine. Thiamine deficiency is only a problem in diets high (as a proportion of calories consumed) in: 1) refined, unfortified grains, 2) refined sugar, 3) excessive alcohol.
From the food.gov.uk website re: recommendations:
"Recommended amounts - Body stores of thiamin are limited and a regular intake is necessary. Thiamin requirement is related to energy consumption. The RNI for adults and children >1 year is 0.4 mg/1000 kcal and 0.3 mg/1000 kcal in infants (COMA, 1991). Assuming food intakes of 2000 kcal/day and 20% losses through cooking, this can be estimated to be 1.4 and 1 mg/day for adult males and females respectively. In pregnancy and lactation, thiamin requirement increases to approximately 1.6 – 1.8 mg/day."
Given that pork loin contains 2mg/100g thiamine and retains 70% of this after cooking, 100g per day is all that is required to avoid deficiency with no carbohydrate intake whatsoever. This amounts to approx 250kcal and 10g of fat. Smear on a teaspoon of marmite before cooking, add in some leafy greens and you have a meal fit for a king.
Low carbohydrate does not mean low in essential vitamins.
Competing interests: I don't eat bread or pasta and have failed to develop a thiamine deficiency