Weight gain and digestive problems during Pessah seem to many people to be the Eleventh Plague. But dieticians say it is possible to avoid these conditions. A basic Seder meal can contain as many as 1,500 calories. A single piece of matza contains 150 calories, about twice the number of calories in a slice of bread. Light matza contains only 85 calories, but is more expensive. Dafna Natan, a clinical dietitian at Maccabi Health Services, notes that unsweetened almond spread is tasty and less fattening than calorie-rich spreads like butter, honey, and chocolate. Another option to help the matza slip down is tehina with silan (date spread) instead of halva, which contains trans fats. Whole wheat matza is more nutritious than that made from white flour, especially for diabetics, Natan says. Whole wheat flour is better for making cakes, and applesauce can replace eggs, which are used a great deal during Pessah, especially by Ashkenazi Jews, who abstain from eating legumes. Eating many servings of vegetables helps digest matza, and smaller, more frequent meals are healthier than heavy meals. Probiotic food such as yoghurt containing "friendly" bacteria, cooked prunes, olive oil and cooked beets can reduce the risk of constipation, advises Yifat Na'an, a clinical dietitian in Pardess Hanna. Taking walks and field trips during the holiday helps eliminate the calories consumed. Dr. Uri Sandovsky, head of the emergency room at Hasharon Medical Center, warns hikers taking precautions against sunburn and snake and scorpion bites. Signs of heat stroke include headache, weakness, thirst and a quick pulse. Meanwhile, Ahiya Kamara, director of the Bekol organization, which advocates for the deaf and hard of hearing, says the hearing disabled should not be allowed to feel left out or unwanted at the Seder. Kamara advises ways of making the Seder pleasant for the hearing-impaired: Seat them so they have a direct line of vision with other participants, to allow them to read lips or hear more easily. Present them with an easy-to-read Haggada. Try to speak clearly and slowly. If you feel a reader has lost his or her place in the ritual, point out where in the Haggada the rest of the participants have reached.