On the morning of Day 7 fasting day , the subjects were questioned to ensure diet compliance. The subjects remained at the research facility performing desk work mostly computer work , and the research personnel who interacted with the subjects throughout the day, assessed compliance to fasting. The measurement protocol consisted of breath ketone acetone measurements performed at baseline, and during acetone buildup.
The measurements were taken after phase 1, and right before starting phase 2, in the morning of Day 6 at am. The baseline levels reflected the acetone level after intake of Diet A on the previous days. These measurements were taken after phase 2 at 12 hours from the last meal on Day 6 which was consumed at pm , and at the beginning of Phase 3 starting at am in the morning of Day 7 fasting day for a period of 9 hours every 1.
The measurement procedure was repeated during each weekly diet protocol. The acetone buildup was calculated as the difference between the acetone levels measured after 21 hours of fasting Day 7 and the baseline level determined in the morning before breakfast of phase 2 Day 6, after consumption of diet A, which was a carbohydrate-rich diet and low-fat diet on Day 5. The method of determining the baseline was chosen over a random measurement of acetone during a regular or uncontrolled day of the subject since breath acetone is known to be affected by diet and physical activity during the day [ 32 ].
H 2 O, which were monitored. Individual subject breath was collected in a 6 L clean bag before immediately being measured with SIFT-MS using a pump at a constant flow rate. The flow rate was monitored and adjusted in the analysis by monitoring the water vapor level in the samples. Blood and urine ketone as well as blood glucose levels were measured every 4. Blood ketones were measured using Precision Xtra, an electrochemical capillary blood monitor from Abbott.
Standard operation procedures as prescribed by the monitor were used for the analysis. The test meter was turned on while a ketone strip was inserted to prepare for the test. A drop of blood was applied to the assigned spot of the ketone strip. Ketone levels were read from the display 10 seconds after blood was delivered to the meter.
Meanwhile, urinary ketone measurements were performed using over-the-counter reagent strips for urinalysis Ketostix from Bayer. The strip monitored acetoacetic acid AcAcA , upon reaction with nitroprusside salt. The reagent end of the strip was passed through the urine stream, changing the color on the strip.
The color was then compared to the color chart provided with the product seconds after the reaction. In addition to ketone analysis, blood glucose was measured for comparison using Precision Xtra, an electrochemical capillary blood monitor from Abbott, and glucose strips, according to the standard procedure as prescribed by the vendors.
All ketones and blood glucose measurements were carried out simultaneously for direct comparison. OriginPro software was used for all statistical analysis.
The effect of a high-fat diet on the level of ketosis was analyzed for statistical significance by performing a two-way repeat measurement analysis of variance ANOVA.
Pair-wise comparisons of three data sets obtained from 11 subjects were performed using Fisher LSD tests. The data sets were related to the acetone buildup concentration due to the three different diets consumed on separate study weeks.
In addition, relationships between ketosis and physiological parameters of the subjects were analyzed using nonlinear regression models keeping the physiological parameter as the independent variable. As mentioned earlier, each week included a different diet taken during phase 2 Day 6 Figure 1. The diets Diets A, B, and C differed in the ratios of fat vs. Figure 2 shows the acetone buildup levels as a function of the ratios of fat to total carbohydrate and protein by mass of the three diets.
Table 3 summarizes the results from Figure 2 , and related statistical tests, and analysis of differential increase percentage of acetone buildup concentration of one diet with respect to another see below for more details. Figure 2 clearly shows that fasting induced significant increases in breath acetone levels after each weekly diet Diet A, B, or C. Changes in acetone during phase 3, starvation, after different diet compositions for 11 subjects.
The diets are defined by the ratio of fat to total carbohydrate and protein by mass, which are plotted on the x-axis. The change in acetone in ppmV is plotted on the y-axis. Comparative table of the effect of Diet A, Diet B, and Diet C on acetone buildup concentration under fasting conditions.
In order to further compare the effect of the different diets on the acetone buildup concentration, a Fisher LDS pair-wise comparison was performed Table 3. For p value of 0. Furthermore, analysis of differential increase percentage of acetone buildup concentration at individual levels Table 3 indicated the following:.
Diet B vs. Diet C vs. With regard to the last comparison Diet B vs. Since, the ketone level in breath is reflective of ketone level in blood, and these levels are a consequence of production vs. However, it is worthy to note that a reduction of fat in diet to meet a ratio of 1. This eliminate cumbersome ultra-high fat needs in ketogenic diets , which are typically associated with nausea and non-compliance [ 33 , 34 ].
A reduction in fat ratio also would mean more food choices to be available which may improve the diet compliance especially in epileptic children under such diets.
In addition, there are several significant observations in the kinetics of acetone buildup among individuals. As an example, Figure 3 shows the acetone buildup among the 11 subjects during starvation phase 3: Day 7 following Diet B 1. The data shows that individuals are different not only in their acetone levels but also in their acetone growth kinetics. This variability indicates the need for personal monitoring of breath acetone in order to choose the most effective diets for development of ketosis in healthy individuals, which leads to investigation of the physical and physiological factors in individuals that determine acetone buildup capability.
Breath ketone, acetone, measured during the starvation day Day 6 for 11 subjects after Diet B. Time zero was set for am in the morning, after 12 hours from last meal pm on Day 5. Figure 4 shows correlations of breath acetone levels with blood ketone, urinary ketone, and blood glucose. The very high breath acetone levels collected from all 11 subjects were confirmed with the high blood ketone and urinary ketone levels.
In addition, the exponential decay relationship between breath acetone and blood glucose also indicated that blood glucose was depleted as breath acetone was produced. Correlation of breath acetone levels with blood ketone and urine ketone as well as blood glucose collected from different subjects on their fasting days. The increase in acetone levels so-called fasting ketosis capability was correlated with different physiological and physical parameters recorded during the study. Though the correlation was weaker with BMI, both correlations still presented the general tendency that subjects with lower BMI produced more acetone.
This finding was in agreement with former assessments presented in literatures [ 35 , 36 ]. At the beginning of the day, 12 hours after the last meal, collected breath acetone in each individual showed expected levels.
Correlation of acetone buildup on starvation day Day 6 after diet C on Day 5 with different physiological parameters. Two subjects with lowest BMI marked in circles did not follow the trend likely due to non-compliance of energy balanced diet on Day 5 of the diet.
However, the absolute values of acetone buildups from this study are higher than previously reported studies as seen in Table 4. The reasons of the differences are rationalized as follows:.
We have observed that during a fasting period, the time from last meal triggers an exponential growth in acetone levels.
Our fasting times are considerably longer, 2. Furthermore, the fat content of the diets administered 22 hours prior to the fasting period of this study are at least 3 to 4 times higher than those used in the previously reported ketogenic diet studies [ 37 ].
Comparative table of acetone buildup conditions for this study and other studies. In addition, no level of energy balance negative or equilibrated is provided to determine whether the subjects had any additional effect from calorie restriction.
As a result, this study shows higher levels compared to the previous studies due to higher fat content in the diets combined with a longer fasting period of 22 hours. The higher levels of ketone buildup were also verified by high urine and blood ketone measurements up to 4.
In addition, the assessed values of urine, blood, and breath ketone for this study were also found to correlate with the urine, blood, and breath acetone levels found in a high ketoacidosis group reported by Qiao, Hu, et al.
Additionally, when combining ketogenic diets with fasting for the next 9 hours, we found exponential growth of acetone levels from all subjects. This is a conclusion that requires further investigation, but in principle, it should be expected that higher metabolic rates might correlate with higher fat burning capabilities, and therefore higher ketone buildup in healthy individuals under NK and FK states.
It is worth noticing, the remaining 2 subjects outliers of the general trend , had relatively low metabolism, and with the least BMI among all the 11 subjects.
An interview with the subjects the next morning revealed they did not comply with the assignment of consuming completely their total supply of food on Day 6. Higher fat content diet did not always induce the most breath acetone, which correlates to fat oxidation. However, more in-depth research needs to be performed to draw further conclusions since our study only examined ketosis buildup over one day of a ketogenic diet and one day of fasting.
Additionally, one small drawback was that the highest fat diet was very difficult to consume. As a result, it was hard to recruit more subjects. In conclusion, the data presented in this study show that while Nutritional Ketosis NK is an effective way to control ketone levels, NK has a great impact on FK in terms of ketone production, which is desirable in certain cases such as seizure control in epilepsy.
On the contrary, most subjects in this study showed similar or better ketosis buildup with a diet of lower fat content. These observations suggest the need for personalized monitoring of individuals for optimization of their diet.
For example, the correlations indicated that subjects with lower fat percentage, BMI, as well as higher metabolic rate REE have higher ketone buildups, and thus metabolize fat more efficiently. We would like to acknowledge compliances from all 11 subjects of the diet study and financial assistance from School for Engineering of Matter, Transport, and Energy, Arizona State University.
Additional file 1: 89K, docx Supplementary data. Amlendu Prabhakar and Ashley Quach contributed equally to this work. Competing interests. What are the differences between ketones, ketosis, and DKA?
These terms are commonly used in the Type 1 community but what do they mean? Here is a breakdown of their definitions and differences. Ketones are a source of energy for the cells in the body. Typically, glucose is used as fuel for cells. When the body is unable to access glucose for fuel, it uses fat stores as an alternative. The liver burns fatty acids and produces usable energy called ketones.
Acetoacetate and beta-hydroxybutyrate transfer energy produced in the liver to the rest of the body. Nutritional ketosis occurs when the body changes the way it gets energy over at least a few days. After the body burns through all of its glycogen stores, or cannot use glucose derived from carbohydrates for energy, it breaks down fat which produces ketones.
In nutritional ketosis, small amounts of ketones are created and used as energy. The body will produce ketones until a more significant serving of carbohydrates is consumed. A diet that is high in fat, moderate in protein and extremely low in carbohydrates can result in nutritional ketosis. An extremely low carbohydrate diet consists of a g carbohydrate limit per day which varies based on body type and exercise.
Diabetic ketoacidosis or DKA is typically caused by a lack of insulin. Normally, insulin takes glucose out of the blood and allows cells to use glucose for energy. Then, fat is burned as a source of energy resulting in ketone production. Shared Applications MEK and Acetone are both utilized as solvents in coatings, lacquer, varnish, and paint. Methyl Ethyl Ketone is very useful in paint, rust, varnish, lacquer, and grease removers. Benefits of MEK Highly effective solvent.
High boiling point. Slow evaporation rate. Soluble with water. Benefits of Acetone Low toxicity. Water soluble. Low boiling point. Fast evaporating.
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