60 Years Later, Where is the Fitbit to Measure Nutrition Status?
Does diet affect health? Of course it does. Vitamin and mineral deficiency diseases are evidence that nutrition is essential. Overweight and obesity are caused by eating more calories than we expend. This implies that obese individuals must eat more. And the insinuation is they probably eat more energy-dense foods too.
Albar and colleagues used 4 day self-reported dietary records from a nationally representative survey of 636 UK adolescents (11-18y). 88% were of white European origin. Data was collected over 3 years(2008-2011). Food items were categorized into 10 food types, 50 food groups and 140 subfood groups. The top 20 high-energy-dense subfood groups were calculated. Total intake was associated with BMI after statistically adjusting for mis-reporting (normal- versus under-reporters), sex and age. A statistically significant association between the percentage of energy intake from each macronutrient and BMI was not observed. Significant associations were observed between a few energy-dense food groups and BMI but not all.
Coming on the heels of a meta-analysis failing to find evidence that increased consumption of fruit and vegetables help prevent obesity, it appears that efforts to vilify food groups for their contribution to obesity speak more to a rapporteur’s food biases than the evidence. The problem with food intake data is that people under-report. Under-reporting in nutritional surveys ranges from 18-54% and can be as high as 70% in some subgroups. Unless a doubly-labeled water method is used as a reference, food intake data is circumspect.
In 1952, Dr Charles King, Scientific Director of the Nutrition Foundation and Professor at Columbia University, wrote “Unquestionably, one of the most damaging practices is simply eating too much. An excessive intake of calories, alone, constitutes a major hazard to health, especially in the upper age bracket, but the prospect of warding off diseases associated with aging is made doubly-hazardous when high calorie foods are low in vitamins, minerals, and good quality protein.”
Over 60 years later, Dr King’s words still ring true: the appraisal of nutritional status needs to be increasingly dependent upon microchemical analysis for vitamins and minerals. It is time for a tipping point in nutrition.
Albar SA, Alwan NA, Evans CEL, Cade JE. Is there an association between food portion size and BMI among British adolescents? 2014 Br J Nutr doi: 10.1017/S0007114514001548
Kaiser KA, Brown AW, Brown MMB, Shikany JM, Mattes RD, Allison DB. Increased fruit and vegetable intake has no discernible effect on weight loss: a systematic review and meta-analysis. 2014 Am J Clin Nutr doi: 10.3945/ajcn.114.090548
Macdiarmid J, Blundell J. Assessing dietary intake: Who, what and why of under-reporting. 1998 Nutr Res Rev doi: 10.1079/NRR19980017
Schoeller DA. How accurate is self-reported dietary energy intake? 1990 Nutr Rev doi: 10.1111/j.1753-4887.1990.tb02882.x
King CG. Basic research and its application in the field of clinical nutrition. 1952 Am J Clin Nutr 1: 1-6.