[Effects of minerals on obesity in different ratios of three energy-supplying nutrients]

To explore the effect of the overall nutritional status of minerals(Ca, P, K, Na, Mg, Fe, Zn, Se, Cu, Mn, I) on obesity under the different proportions of three energy-supplying substances in the diet of the population.

Population monitoring data(a total of 9734 cases aged 20-74 years old) from the cross-section of diet, nutrition and non-communicable chronic diseases in Harbin in 2012(stratified random sampling method was adopted) were selected.Questionnaire and 24-hour dietary information were conducted by trained professionals. Height, weight and waist circumference were measured by uniform standard measurement method;The energy supply ratio of carbohydrate, fat and protein was calculated and a three-point stratification was carried out to construct different proportion patterns of the three energy-supplying nutrients. Logistic regression was used to analyze the risk relationship between the proportion patterns with the top 3 highest frequency and obesity. Energy density method was used for energy correction of Ca, P, K, Na, Mg, Fe, Zn, Se, Cu, Mn and I. Mineral equilibrium index was constructed with Se as reference, and Logistic regression was used to analyze the risk relationship between mineral equilibrium index and obesity. To analyze the relationship between the interaction of three proportions of three energy-supplying substances and the mineral balance index and the risk of obesity.

The energy supply ratio of carbohydrate, fat and protein was stratified in a third and 27 combinations were constructed, respectively representing the different proportions of the three energy-supplying substances in the dietary pattern of the population. The proportion of high carbohydrate, low fat and low protein(known as the dietary structure of low fat) was 1583 cases, accounting for 16.3% of the total population.Secondly, the proportion of low-carbohydrate, high-fat and high-protein(called high-fat diet structure) was 1580 cases, accounting for 16.2% of the total number. The third was the relative balanced proportion of carbohydrate, fat and protein(called balanced diet structure) in 1122 cases, accounting for 11.5% of the total population. Compared with the balanced diet group, both the low fat diet group and the high fat diet group increased the risk of obesity and had statistical significance. OR value and 95% confidence interval were 1.251(1.017-1.538), 1.311(1.069-1.608), respectively, the P value was 0.028. The smaller the absolute value of mineral balance index was, the closer the population's mineral intake was to the recommended intake(refer to the recommended amount of mineral diet of China nutrition association in 2013). The larger the absolute value of mineral balance index was, the greater the deviation between the population's mineral intake and the recommended intake was. When the absolute quartile of the mineral balance index was grouped, the risk of obesity was increased in the second, third and fourth quartile groups compared with the first quartile group. OR value and 95% confidence interval were 1.221(1.038-1.435), 1.233(1.048-1.450), 1.179(1.003-1.388), respectively, P value was 0.050. A positive mineral balance index indicated that the mineral intake was greater than the recommended dietary intake, and a negative mineral balance index indicated that the mineral intake was less than the recommended dietary intake. The population with positive values of each mineral was screened and divided into four groups. Compared with the first group, the third and fourth groups could increase the risk of obesity. The OR value and 95% confidence interval were 1.221(1.038-1.435), 1.233(1.048-1.450), 1.179(1.003-1.388), respectively, P value was 0.050. Carbohydrate, protein and fat dietary structure, the proportion of three kinds of interactions with mineral balance index also affected the risk of obesity, the first points of the minerals in combination with balanced diet balance index, compared to a set of low fat diet combined mineral balance index of 4 points a, with high fat diet and mineral balance index points 2 and 3 a group can increase the risk of obesity, the OR value and 95% confidence interval were 1.352(1.083-1.687), 1.319(1.000-1.742), 1.540(1.143-2.076), the P value was 0.037.

There are different proportions of energy-supplying nutrients in the diet of the population, and the imbalance of intake significantly increases the risk of obesity. Mineral intake of unbalanced nutritional status will also significantly increase the risk of obesity. It is important to note that even when minerals are abundant, the imbalance increases the risk of obesity. An imbalance in intake of energy and minerals further increases the risk of obesity, compared with the three groups in which energy and mineral intake are relatively balanced. As a whole, minerals are affected by the dietary structure of three major energy-supplying substances while influencing obesity.