Both your nutritional needs (the food and water) and your metabolism (how fast your body converts food to energy) change at this age. Your metabolism gets slower. Women lose about half a pound of muscle per year starting around the age of 40. That makes losing weight even more difficult. Some of the changes women experience are due to decreased hormones, reduced activity level, and medical conditions.
Use MyPlate (PDF – 281 KB) as a guide to build a healthy diet. Think about filling your plate with foods from the five food groups — fruits, vegetables, grains, proteins, and dairy — at each meal. Snacks can be a good way to fill in fruits and whole grains you might have missed at meals. Most of us don’t need complicated calorie counting programs or special recipes for healthy eating.
Fluids: Fluid needs increase as women age. The reason: Kidneys become less efficient at removing toxins. “Drinking more fluids helps kidneys do their job,” Schwartz says. “Unfortunately, thirst signals often become impaired with age, so people are less likely to drink enough water and other fluids.” Rather than fret about how many glasses to drink, Frechman says, check the color of your urine. "It should be clear or very pale colored. If it becomes darker, you need more fluid.”