The Day Before You Dive
You should eat less than you typically would, dropping around 500 calories from your normal dietary intake. Avoid trying new exotic foods as well as fried foods, oil based foods and alcohol. Eat Fruits, veggies, water, cereal, and lean protein to prepare for your dive.
Be sure to eat at least 2 hours before your dive. Eating complex carbs like brown rice or sweet potatoes that provide a steady release of energy is ideal. Good food choices include whole grains, boiled eggs, fruit, and lean protein. Avoid greasy and fatty foods the morning of your dive. Small portions will help keep nausea at bay and make your dive more comfortable, decreasing the risk of nausea and indigestion. Between dives during your surface interval, eat fruit or high carb snacks to replenish your energy. Not eating before a dive can lead to loss of consciousness and difficulty with thermoregulation. Eating too much can lead to nausea and vomiting.
You also want to avoid alcohol on diving day. It can lead to dehydration which increases risk of DCS, or Decompression Sickness. It also contributes to nausea/vomiting and impairs judgement. Alcohol also masks symptoms of Nitrogen Narcosis, which can become a dangerous situation for all divers in the water. Drink enough water to hydrate but don’t over do it, a full belly of water or even a full bladder are not the most comfortable in a wetsuit. Being well hydrated can help prevent cramps and decompression sickness. Take only small sips of water 30 minutes or less before diving.
Common Health Conditions and Diving
Diving and Cholesterol
There is a possible correlation between high total cholesterol and “bubble-proneness” following altitude decompression. There is an increased risk of a cardiac event occurring during a dive for divers with elevated triglycerides as well. Be aware that lipid lowering medications can resemble DCS symptoms like paresthesia (numbness and tingling), dizziness, fatigue, muscle and joint pain. It’s best not to begin taking a cholesterol lowering medication just before a dive trip so that any side effects won’t be mistaken for DCS.
Diving and Obesity
Maintaining proper weight is important for diving safety. Obesity leads to increased risk of cardiac incidents while diving. A DAN, Divers Alert Network, study showed those with a BMI of 30+ accounted for 53% of dive related deaths. Those with a BMI of 18.5-24.9, which is the range established for a healthy BMI, accounted for 13% of dive related deaths. BMI is your weight (in kilograms) over your height squared (in centimeters). Also of note, fat has more nitrogen, but a poor blood supply. Excess fat in a recreation diver does not accumulate enough nitrogen to increase their risk of decompression sickness. However, obesity increases risk for DCS when diving daily over several days or diving a lot in a short period of time due to increased nitrogen levels in the fatty tissue. The deeper the dive the more nitrogen accumulation, leading to increased risk, with tech and rebreather divers.
Diving and Diabetes
Divers diagnosed with diabetes are still able to enjoy the sport of diving. It’s important to keep your blood sugar level stable; your doctor may even recommend skipping your glucose lowering medications the morning of your dive to avoid low blood sugar levels. To help keep your diabetes under control, eat foods that give you energy, such as leafy greens that are high in folate and mood enhancing. Whole grains are ideal, as they digest slowly and help maintain stable blood sugar levels. Bananas are rich in potassium, needed for proper muscle and nerve function, while nuts are full of good fats, protein and magnesium, also great for energy. Incorporate lean meats which are high in tyrosine, boost dopamine, and increase alertness and focus. Beans are a good source of protein and sustained energy source, while curry, chili peppers, turmeric and cumin promote circulation. Quinoa, a grain full of protein, is also a great energy booster.
Foods That Protect Divers From The Sun
Foods high in Vitamin C like red bell pepper, strawberry, broccoli, papaya, Brussels sprouts, spinach, and tomatoes are great for natural sun protection. Foods high in antioxidants such as red and purple grapes, blueberries, raspberries, red kidney beans, cranberry, prunes, leafy greens and artichokes can help protect your skin from sun damage. Watermelon is high in lycopene, which has sun protective properties. Walnuts, chia and flax seeds, and fatty fish like salmon and mackerel are high in omega-3 fatty acids which help maintain skin’s integrity. This is an important consideration for divers who spend a lot of time in the sun. Carrots, cantaloupe, kale and sweet potatoes rich in beta carotene protect the skin and eyes from UV damage. Green tea’s flavanol reduces skin damage from UVA light and protects against collagen decline. Collagen is responsible for skins firmness. Cauliflower’s histidine stimulates uronic acid which absorbs UV radiation.
Supplements Good for Diving
Fish oil high in omega-3 fatty acids may offer a potential reduction in decompression sickness injury. Ginseng improves physical and cognitive performance while vitamins C and E are antioxidants that offset the strain of diving on the cardiovascular system. Digestive enzymes help breakdown food and can help avoid upset stomach while diving. Ashwagandha, an adaptogenic herb, relieves stress and anxiety while improving energy and alertness, a great benefit for scuba divers. Peppermint, ginger root and lemon balm make a great anti-nausea combination.