Patricia Thompson - NUTRITION TALK IS THE heat of summer sapping your energy? Do you feel sluggish, suffering from headaches, impaired concentration or less frequent and less bulky bowel movements in these summer months? Then, you may not be consuming enough fluid. If your weight at the end of the day is less than in the early morning, you may not be taking in enough fluid to balance that lost by perspiration and urine. Some persons find frequent drinking a nuisance while others avoid drinking to reduce their frequency of urination.
HOW MUCH WATER IS NEEDED?
Textbooks recommend six to eight glasses daily. This will meet your obligatory needs for water and is fine for people indoors or in air-conditioned offices and cars. However, if you are outside during the day and perspire a lot, you may need more like 12 glasses of fluid daily. The type of diet also affects water needs. High protein diets require more water since they result in greater water loss than the normal diet.
In addition to the basic need, you can be guided by your weight loss due to sweating. Athletes in training and persons working in the direct sun may lose two per cent of body weight as sweat in one hour without realising it and this will severely impair work output.
A loss of five per cent (about eight pounds) is indicative of dehydration and this must be replaced with 16 glasses of liquid. Every pound lost as water weight represents an additional two glasses (500mls) of fluid.
Some of the fluid needed is provided by the food eaten, especially succulent fruits, but the rest must be drunk. Plain water could provide the rest of this fluid but some persons find it unpalatable and have difficulty consuming such large volumes. In fact, this may not be the most efficient method of hydration as large volumes of plain water at a single sitting stimulates the water flushing body systems and cause greater water loss.
WATER ABSORPTION
A little flavour and solute in the water may improve water absorption by the body. Too high a concentration, however, impairs water absorption. The maximum concentration recommended is one level tablespoon carbohydrate (sugar) per glass of fluid. If you use highly-sweetened drinks, therefore, for every ounce of drink you should consume an additional two to three ounces of plain water.
If you drink water with your meals, the solid food will provide the solute needed for absorption so the extra sugar would not be needed. Remember that each tablespoon of sugar has 46-60 calories and the calories consumed from drinks should fit into your total caloric intake. Water has zero calories, coconut water has 50 per glass while fresh juices have 100 and sweetened juices and drinks vary from 110-200 calories per glass. Also, cool water is better absorbed than warm.
WHEN TO DRINK
A strategy for conserving the water drunk is consuming frequent small quantities throughout the day. Ensuring adequate hydration between meals is necessary to prevent cravings or even overeating at meal times. Your thirst and hunger centres sit side by side in the brain and under-stimulation of the thirst centre may trigger hunger.
Persons interested in good health should get in the habit of consuming water throughout the day. A practical measure of your hydration status is the frequency of urination along with the colour and volume of urine. Infrequent urination with a dark-coloured urine and relatively small volume is an indication of poor hydration.
Patricia Thompson M.Sc., Registered Nutritionist, Nutrition and Diet Services; email: yourhealth@gleanerjm.com.
