Measurement of the Thermic Effect of Food in a Chinese Mixed Diet in Young People

Objective To determine the thermic effect of food(TEF)in a Chinese mixed diet in young people.Methods During the study,the participants were weighed and examined for body composition every morning.The total energy expenditure(TEE)of the participants was measured by the doubly labeled water method for 7 days,and during this period,basal energy expenditure was measured by indirect calorimetry and physical activity energy expenditure was measured by an accelerometer.The value obtained by subtracting basal energy expenditure and physical activity energy expenditure from TEE was used to calculate TEF.Results Twenty healthy young students(18–30 years;10 male)participated in the study.The energy intake of the participants was not significantly different from the Chinese Dietary Reference Intake of energy(P>0.05).The percentage of energy from protein,fat and carbohydrate were all in the normal range.The intakes of fruits,milk and dietary fiber of the participants were significantly lower than those in the Chinese Dietary Guidelines(P<0.05).There was no significant difference in the body weight of the participants during the experiment(P>0.05).When adjusted for body weight,there was no significant difference in either TEE or basal energy expenditure between the male and female participants(P>0.05).In addition,there was no significant difference in physical activity energy expenditure and TEF between the male and female participants(P>0.05).The percentage of TEF in TEE was 8.73%.Conclusion The percentage of TEF in TEE in a Chinese mixed diet in young people was significantly lower than 10%(P<0.001).A value of 10%is usually considered to be the TEF in mixed diets as a percentage of TEE.

The Effect of Different Diet on Saliva

The aim of this scientific research was to study the influence of various diets (ketogenic, low carb, mixed) on teeth and saliva structure of healthy individuals. The health condition of teeth and the influence of diet (sweets, water intake) were investigated using the questionnaires which were statistically processed by descriptive and inductive statistics. Saliva was examined using synchronous fluorescent fingerprint (SFF) and atomic force microscopy (AFM). The statistical evaluation of answers of respondents using the questionnaires about intake of sweets in their diet showed significant influence of sugars on formation of tooth decay of diet. The intake of water (volume and frequency) did not show significant influence on formation of tooth decay. Endogenous fluorescence and surface structure of saliva differed in healthy subjects with different diet. The most organized surface structure showed low carb diet (without crystals). The least organized surface structure showed ketogenic diet with the big crystals (1 - 2 μm). Untraditional methods (SFF and AFM) enable the new, sensitive and quick analysis of the mixture of saliva. Saliva of individuals with low carb diet showed the most organized structure. Low content of sugar in diet is important possibility of the prevention before dental carries.

Evaluation of the Protein Requirement in Chinese Young Adults Using the Indicator Amino Acid Oxidation Technique

Objective To accurately calculate the protein requirements in Chinese young adults using the indicator amino acid oxidation technique. Methods Nine women and ten men received a restricted daily level of protein intake （0.75, 0.82, 0.89, 0.97, and 1.05 g/kg）, along with L-[1-13C]-Ieucine. Subjects＇ protein requirement was determined by a biphasic linear regression crossover analysis of F13C02 data. In doing so, a breakpoint at the minimal rate of appearance of 13C02 expiration specific to each level of dietary protein was identified. This trial was registered with the Chinese clinical trial registry as ChiCTR-ONC-11001407. Results The Estimated Average Requirement （EAR） and the Recommended Nutrient Intake （RNI） of protein for healthy Chinese young adults were determined to be 0.87 and 0.98 g/（kg.d）, respectively, based on the indicator amino acid oxidation technique. Conclusion The EAR and RNI of mixed protein are 5% and 16% that are lower than the current proposed EAR and RNI {0.92 and 1.16 g/（kg.d）, respectively）, as determined by the nitrogen balance method. The respective EAR and RNI recommendations of 0.87 and 0.98 g/（kg.d） of mixed protein are estimated to be reasonable and suitable for Chinese young adults.