Are We Born with All of the Fat Cells We Will Ever Have

We are not born with a full complement of fat cells as some scientists once thought. The number of fat cells in the body increases at various stages throughout growth, but by the time adulthood is reached the total number of these cells can become fixed. This means that if our body fat mass does not change, we probably would not produce new fat cells as adults. However, if we consume excessive calories, the number of fat cells can increase. In adipose tissue there is a small number of so-called...

Metabolism Equals Energy Expenditure What Is Metabolic Rate

The chemical reactions that take place in our cells release energy, and this energy is ultimately derived from the breakdown of energy nutrients namely carbohydrate, protein, fat and alcohol. Over the course of the day almost all of the energy released will be converted to heat and lost from the body. Metabolism refers to the sum of the energy (calories) generated in our body and lost as heat. To go a little further, metabolic rate is the amount of heat we produce within a specified period of...

How Much Does Different Tissue Contribute to RMR

Looking specifically at basal metabolism occurring within different tissues in the body we find that the most metabolically active tissue (calories expended gram tissue) are the vital organs, namely the heart, kidneys, lungs, pancreas, brain, and liver. While only making up roughly 10 percent of our body weight, these organs accounts for as much as 50 to 60 percent of our RMR. Interestingly, the retina of the eye is the most meta-bolically active tissue (per gram of tissue). Meanwhile, the...

How Are the RDAs Determined

The RDAs are determined based upon in-depth research studies, including those performed to determine balance. Balance studies are designed to determine how much of a specific nutrient humans need to eat in order to balance that which is normally lost daily from the body and to maintain appropriate levels of that nutrient in the body. When these studies were performed, scientists observed that there was quite a bit of variability among the balances of different individuals. A hypothetical...

Can Fortified Water Fitness Water Help Performance

Over the past few years numerous enriched waters or fitness waters such as Propel and Option . These beverages tend to be low calorie (for example, 10 calories per 8 to 10 ounces) and include electrolytes with or without calcium, magnesium and B-vitamins. While these beverages are not advantageous for more strenuous and or prolonged athletic efforts they are good options for maintaining optimal hydration especially in the heat (for example, walking or a half hour or so on the elliptical or...

Major Minerals Include Calcium Phosphorus and Electrolytes

The major minerals make up most of the mineral in our body by weight. Because of this our dietary needs are higher than minor minerals. In addition to foods, supplements make a significant contribution to many people's intake. For instance, calcium-based supplements are among the most popular with consumers who take them primarily for bone support. Without question calcium is one of the most recognizable and popular minerals. Perhaps this is well deserved, as calcium is about 40 percent of...

Can Glutamine Slow Muscle Breakdown

Glutamine is a nonessential amino acid that has become a popular supplement for weight lifters and bodybuilders. It has been touted as a supplement that causes a net gain of muscle protein and thus muscle mass. From the discussion of proteins, you will recall that body proteins are broken down and rebuilt on a daily basis. This is called protein turnover and it reflects the dynamic efforts of our cells to adapt to metabolic conditions that change minute by minute, hour by hour, and day by day....

Vitamin B

Vitamin B6 is the general term for the six compounds, namely pyridoxal (PL), pyridoxine (PN), pyridoxamine (PM), and their phosphate derivatives including pyridoxal 5'-phosphate (PLP), pyridoxine 5'-phosphate (PNP), and pyridoxamine 5'-phosphate (PMP). It is the PLP form that is the most significant in human operations. Although long recognized for its pivotal role in the processing of amino acids, vitamin B6 has received attention for its role in homocysteine metabolism and in reducing...

Can Chromium and Chromium Picolinate Cause Muscle Development

Chromium, especially in the form of chromium picolinate, has drawn the attention of some athletes. Because chromium appears to potentiate insulin activity, it has been theorized that supplemental chromium may increase amino acid uptake in skeletal muscle and promote muscle protein synthesis. This could lead to the building of more muscle. Picolinate is simply a molecule that, when bound to chromium, is touted to enhance the efficiency of chromium absorption. Earlier reports by some researchers...

How Efficient Is Fat Digestion and Can We Decrease Fat Absorption

The efficiency of the digestion and absorption of the fat and cholesterol we eat is greater than 90 percent. Certain drugs and dietary supplements have been marketed to reduce the absorption of fat from the diet. For instance, the supplement chitosan is fiber-like substance derived from chitin. Chitin is a polysaccharide-like structure made up of amino sugars (sugars with nitrogen) which helps harden the shells of shellfish (shrimp, lobster, crab), insects (beetles), and is also found in some...

What Is Margarine

Margarine was first developed in the nineteenth century as an alternative for butter. Early on it was a popular butter substitute for people who could not afford butter or to whom butter was not available. Margarine can be made from animal fats and or vegetable oils however, the bulk of margarine containing products today use vegetable oil based margarines. This is partly attributable to the relationship between a diet high in saturated fat in animal fat and the risk of heart disease. Plant...

How Do We Measure Metabolic Rate

Our body works very hard to maintain its temperature at around 37 C (98.6 F). This means that excess heat generated by chemical reactions in cells must be dissipated. Because this dissipated heat is a direct indicator of our metabolism, we can use an insulated chamber sensitive to temperature change to determine how much heat we produce (energy expenditure). This method of estimating metabolic rate is often referred to as direct calorimetry. Calorimetry literally means heat measurement....

Can DHEA and Androstenedione Enhance Testosterone Levels

Dhea Androstenedione

DHEA and androstenedione are prohormone molecules. When the body makes sex hormones such as testosterone and estrogens, they are actually constructed during several chemical reactions beginning with cholesterol. In the gonads ovaries for females and testes for males cholesterol can be completely converted to testosterone and estrogens and released into the blood. Two molecules along the way to the sex hormones are DHEA dehydroepiandrosterone and androstenedione, with the former coming just...

Fluorine F

In nature, the element fluorine exists as a negatively charged atom or ion. Thus, similar to iodide iodine and chloride chlorine , we commonly refer to fluorine as fluoride F- . Fluoride salt NaF is routinely added to toothpaste. What Are Fluoride Sources in the Human Diet Most foods are poor sources of fluoride and probably should not be used exclusively to meet the human body's needs. However, the process of adding fluoride to drinking water fluoridation has greatly improved general fluoride...

What Does Cortisol Do to Help Maintain Blood Glucose Levels During Fasting

Cortisol is often regarded as the stress hormone. It is important to realize that fasting, especially prolonged fasting, is a form of stress and stress results in the release of cortisol from the adrenal glands along with epinephrine mentioned in the previous question. Cortisol also supports the breakdown of glycogen and the conversion of amino acids, lactate, Table 4.5 Actions Of Insulin, Glucagon, Cortisol, and Epinephrine in Carbohydrate Metabolism Insulin Increases the uptake of glucose by...

Where Do High Density Lipoproteins Come From and What Do They Do

HDL is made in our liver and to a lesser extent in our intestines. It is HDL's job to circulate and pick up excess cholesterol from tissues throughout our body and return it to the liver. The whole process is very interesting because in order for circulating HDL to return the cholesterol to our liver, some of the cholesterol is first passed to circulating LDLs. The LDL is then subject to removal from our circulation by the liver and broken down. HDL delivers...

Nervous Tissue Is Electrical and Excitable What Is Nervous Tissue

Nervous tissue is composed mostly of nerve cells or neurons, which serve as the basis for an extremely rapid communication system in our body. It also provides the basis for thinking. The central nervous system includes the brain and spinal cord and represents the thinking and responsive portion of our nervous tissue. Links of neurons extend from the central nervous system to various organs and tissues in our body, thus allowing the central nervous system to regulate their function. In...

Are There Advantages to Storing Energy as

Storing excess energy as fat rather than as protein or carbohydrate has great advantages. First, we are able to store more than twice the amount of energy in 1 gram of fat 9 calories as we can in 1 gram of carbohydrate or protein 4 calories . Second, stored fat will have a lot less water associated with it than would be stored in carbohydrate and protein. The net effect of storing excess diet energy as fat versus carbohydrate or protein is that our body weight and volume are minimized. Said...

What Foods Provide Us with Triglycerides and Cholesterol

As displayed in Table 5.3, fats and oils, and thus triglycerides, are present in both animals and plants. Oil is a natural component of many plant tissues including leaves, stem, roots, kernels, nuts, and seeds. Common edible oils include sunflower, safflower, corn, olive, coconut, canola, and palm oil. Contrarily, butter is made from the fat in milk, while lard is hog fat, and tallow is the fat of cattle or sheep. Other animal flesh will contain fat, including poultry and their eggs....

How Does Epinephrine Adrenaline Help Maintain Blood Glucose Levels During Fasting

During a fasting period, a little epinephrine adrenaline is released into circulation from our adrenal glands see Figure 4.3 and Table 4.5 . Among epinephrine's many roles will be its influence upon the liver and skeletal muscle. It will support the effects of glucagon in the liver that were just mentioned. In skeletal muscle, the slightly elevated epinephrine will lightly promote the breakdown of glycogen to glucose. Contrary to the glucose produced from the breakdown of liver glycogen, this...

Is Being Overweight and Obese Due to Genetic Reasons

This is a difficult question to answer in the manner in which we would like it to be answered. Quite simply, obesity results from an energy calorie imbalance whereby more energy is brought into our body than is expended. We store the bulk of excessive energy as body fat and the weight gain also includes supporting materials such as connective tissue, muscle, bone, etc. Certainly that seems simple enough. However, identifying the underlying reasons for the imbalance is a bit more complicated. Is...

What Are Nutraceuticals and Functional Foods

The latter portion of the twentieth century was a time of great strides in modifying the way many nutritionists and health care practitioners viewed nutrition. For decades we made nutritional recommendations based upon what needed to be avoided or limited in our diet choices. The nutritional bad guys were fat, which evolved to saturated fat-rich foods, cholesterol, sodium, and arguably sugar. Today it is quite clear that the other side of the nutrition coin, or what we should eat, is probably...