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Nutrition

What's the deal with Cholesterol?

By ekoziarski on Sun, 01/16/2011 - 7:57pm

 

This topic was requested by John who wanted some clarification about the difference between fat and cholesterol, and why some foods are high in cholesterol, but not in fat. 
Cholesterol is like fat, but it is not fat. It performs different functions in the body, both good and bad. There is cholesterol in every cell in the body, and also in some hormones. One of its functions is that it helps the body digest and absorb fat.  Also, in sunlight, cholesterol in the skin is converted to vitamin D. 
There are two different types of cholesterol: the kind found in the blood and the kind found in food. Some of the cholesterol found in blood is produced by the body. If the body produces too much, the risk of heart disease increases. Extra cholesterol produced by the body is either changed into body fat or it can build up in the arteries.
The cholesterol in food exists only in those made from animals (meat, fish, poultry, dairy, eggs). Eating a large amount of dietary cholesterol could increase blood cholesterol , but some people are more sensitive to the cholesterol in foods than others. Cholesterol in food does not automatically become blood cholesterol. Intake of fat in food has more of an effect on blood cholesterol than does the cholesterol in food. Specifically, foods that are high in saturated fat cause an increase in bad (LDL) cholesterol. Some foods are very high in cholesterol, yet very low in saturated fat. These foods include crab and shrimp, and are much less likely to increase blood cholesterol than foods that are high in saturated fat such as fatty cuts of beef, butter and cheesecake.
Duyff, L. D. The American Dietetic Association’s Complete Food & Nutrition Guide, 1998.

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Is there a specific diet for swimmers?

By ekoziarski on Sun, 12/19/2010 - 10:09pm

 

This month’s topic is in response to two questions posed by Mr. Mark Royko:
“Should swimmers have a different diet than other sports?” AND
“What is the recommended amount of calories for swimmers like us?”
The optimal diet for swimmers who compete in short to medium distance races (50-1,500 yards/meters) is high in calories, and necessitates a good balance of nutrients.  
·         Energy needs: 35-50 calories/kilogram (3200-4500 calories/day for a 200 lb person depending on the level of training)
·         Protein needs: 1.2-1.7 grams protein/kilogram (110-155 grams protein per day for a 200 lb person)
·         Fat needs: about 1 gram fat/kilogram (91 grams fat per day for a 200 lb person)
As shown above, carbohydrate should make up about 55-65% of energy intake. This is important because carbohydrate is the main source of energy for muscles and the brain. If an insufficient amount of carbohydrate is consumed, athletic performance will decrease because the body will have to resort to attaining energy from breakdown of muscle protein or fat, which are not as efficient as using the carbohydrate stored in muscles and or in the blood.
Protein should make up about 14% of energy intake. Protein is needed for building and re-building of muscle mass, but is not the best source of energy for the body. If too much protein is consumed, it will be broken down and stored as fat or excreted in the urine.
Fat should make up 20-25% of energy intake. Adequate fat intake is necessary to meet essential fatty acid requirements. Fat also aids in producing satiety after eating. Additionally, too little fat can lead to decreased HDL levels and impairment of immune function. However, fat should be limited to 20-25% of energy intake for swimmers to allow carbohydrate and protein needs to be met without exceeding calorie needs. Healthy sources of fat include omega-3 fatty acids. These can be attained from mackerel, albacore tuna, salmon, sardines, lake trout, soybean oil and canola oil. Less healthy sources of fat include saturated and trans fats. These should be eaten in smaller amounts. Saturated fats can cause an increase in your LDL (bad) cholesterol and can be attained from meat, poultry, butter, whole milk, coconut, palm oil and palm kernel oil. Trans fats cause an increase in your LDL (bad) cholesterol and a decrease in your HDL (good) cholesterol. These are unsaturated fats processed to make them stable and solid at room temperature. They are most often found in highly processed foods.
Under-eating is common among swimmers. This is likely related to unnecessary pressure to lose weight because of the amount of time spent in swim wear. Some may need to realize that they may not need to lose weight to improve their health or performance.   Swimmers are one type of many athletes who are at risk for eating disorders.  Inadequate energy intake can lead to insufficient intake of calcium, iron, zinc and vitamin E.  For this reason, all swimmers should take a multivitamin.
With all this being said, there is an optimal weight to strength ratio for every athlete that will help maximize their athletic performance. This means that there is a weight that will provide an optimal amount of muscle to produce maximum strength for an individual combined with a small amount of body fat that will not increase weight to the point that it deters performance. Nutrition is key to attaining this desired weight to strength ratio. Over-training will only lead to injury. Athletes should be mindful that performance will decline if energy, carbohydrate and protein intake are reduced too much in efforts to attain this weight. Major changes to diet for the goal of weight loss should always be made in the off-season or preseason so that performance is not sacrificed during competition.
Hydration should occur before, during and after training. Each athlete should compare his or her pre and post training weights, and consume the difference in fluid after training.  It is also important to monitor urine color, which should be light yellow. Caloric sport drinks should be limited if the athlete is trying to reduce energy intake, but may be needed if sweat is lost during training or the athlete is having trouble maintaining  their blood sugar level during training.

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Nutrition Tip of the Month (November 2010)

By ekoziarski on Sat, 11/20/2010 - 6:19pm

Always refuel after your workouts. Eat a meal or snack consisting of carbohydrate and protein within 30 minutes of exercise to start the process of rebuilding your muscle.


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Vitamin D for Athletes

By ekoziarski on Sat, 11/20/2010 - 6:17pm
Because vitamin D plays a role in numerous physiological functions including gene modulation, immune function, protein synthesis and calcium absorption, it is likely a key to maximizing athletic performance. Muscle pain and weakness which occur in diseases such as rickets (the weakening and softening of bones in children, usually because of significant and long-term vitamin D deficiency) have been shown to subside with supplementation of vitamin D. There are few studies that demonstrate the direct relationship between vitamin D status and performance of athletes. However, there are studies that show improvement in aerobic fitness, jump height, velocity and power among individuals who are not athletes, but known to be deficient in vitamin D.
Vitamin D can be obtained not only from food sources, but also from exposure to sunlight. Production of vitamin D from sunlight depends on time of exposure, season, latitude, cloud cover, smog, skin pigmentation, age and sunscreen use. Unfortunately, in the winter months, it cannot be synthesized in latitudes greater than 35⁰ and 37⁰ north or south. (Chicago is located between 41⁰ and 47⁰ degrees north.)
Good dietary sources of vitamin D include egg yolks (25 IU), fatty-fish such as tuna (154 IU for 3 oz canned), salmon (794 IU, sockeye, 3 oz), sardines (46 IU for 2, canned in oil) and mackerel (388 IU, 3 oz cooked), breakfast cereal (40 IU for about 1 cup), irradiated mushrooms (400 IU for 3 oz), yogurt, fortified milk (120 IU in 1 cup), some brands of margarine (60 IU, 1 tablespoon), and fortified orange juice (100 IU in 1 cup).
From birth to the age of 50, individuals need 200 IU of vitamin D per day. Individuals aged 51-71 need 400 IU per day, and those over the age of 71 need 600 IU per day.
Information adapted from:
 “What Sports Dietitians Should Know About Vitamin D”, Fall 2010 Issue of SCAN’s Pulse.
Dietary Fact Sheet: Vitamin D (http://ods.od.nih.gov/factsheets/VitaminD/)

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