Before you adjust your diet, though, keep reading to learn the facts about five persistent summer food myths. The truth might surprise you.LordHenriVoton/iStockPhoto / Getty Images
Don’t swim on a full stomach. Drink cold water to cool down. Avoid sugary watermelon.
Chances are, you’re familiar with these summertime diet recommendations, along with many others.
Before you adjust your diet, though, keep reading to learn the facts about five persistent summer food myths. The truth might surprise you.
Watermelon isn’t healthy because it’s too high in sugar
The truth: This quintessential summer fruit has less sugar than many other types of fruit.
One cup of diced watermelon, for example, has 9.4 g of natural sugar (and only 45 calories). Compare that to one cup of pineapple chunks (16 g of natural sugar), one cup of blueberries (15 g) and one small apple (15.5 g).
Unlike refined sugar, the natural sugar in fruit comes packaged with fibre, vitamins, minerals and antioxidants. Plus, fibre in fruit slows the body’s absorption of its natural sugars.
Watermelon is, in fact, quite nutritious.
More from Leslie: The four summer vegetables you should be eating now
It contains 91 per cent water, which can help hydrate you on a hot summer day. One cup of diced watermelon serves up nearly two-thirds of a cup of water.
Watermelon also supplies a hefty amount of lycopene, a potent antioxidant thought to help guard against prostate cancer.
And it’s an exceptional source of L-citrulline, an amino acid the body uses to synthesize nitric oxide, a molecule that helps relax blood vessels.
Wait 30 minutes (or longer) after eating before you swim
Apparently, this well-intentioned summer advice has been around since at least 1908, when it was published in the U.S. Boy Scout Manual (without any references) warning boys to wait at least 90 minutes after eating before swimming…or they might drown.
The theory goes that because the process of digestion diverts some blood flow from your muscles to your gut (which is true), this could cause severe leg cramps leading to fatigue during swimming.
However, there’s no scientific evidence to support this notion.
In 2011, the American Red Cross Advisory Committee published a scientific review concluding there was no evidence that swimming soon after eating causes leg or stomach cramping. And there had not been one reported case of drowning caused by swimming on a full stomach.
Still, if you’re planning to go for a strenuous swim, doing so after a meal can make you feel uncomfortable and slow you down. Generally, it takes up to four hours for a mixed meal to completely empty from your stomach.
Burgers are safe to eat when they’re no longer pink inside
Not true. When it comes to food safety, colour is not a reliable indicator of doneness.
Beef patties may be brown in the centre after reaching a safe internal temperature of 71 degrees Celsius (160 degrees Fahrenheit), but they can also remain pink after being safely cooked.
On the flip side (no pun intended), burgers can also turn brown inside before reaching a safe temperature.
The issue: Beef may contain harmful bacteria that cause food poisoning such as E. coli, salmonella and Campylobacter. Grinding beef allows any bacteria present on the surface to be mixed throughout the meat.
The only reliable way to tell if your beef burger is safe to eat is to use a digital meat thermometer.
In hot weather, drink cold water to cool down
The idea that cold water is best for hydrating in the heat comes from studies suggesting it empties from the stomach faster than room temperature water.
As a result, cold water will be absorbed into the bloodstream and hydrate your body more quickly.
Turns out, the quicker gastric emptying effect of cold water is short-lived and the overall difference between the rate at which cold and warm water leave the stomach is minimal.
How well do you know Canada’s iconic ice cream flavours? Take our quiz and find out
Whether you prefer your water colder or warmer, what matters most is staying hydrated.
It’s recommended that women and men drink 9 cups (2.2 L) and 12.5 cups (3 L) of fluid each day, respectively, and more when the weather is hot and humid.
If you’re an endurance athlete, though, studies suggest drinking cold water (0.5 degrees C) during exercise can help reduce core body temperature and improve performance.
Eating barbecued meat can cause cancer
It’s true that grilling meat at high temperatures produces two compounds – heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) – which, in lab studies, have been demonstrated to cause changes in DNA that may increase the risk of cancer.
At high doses, they’ve also been shown to induce tumours in rodents.
In humans, though, there is no conclusive evidence that high intakes of grilled meat increase cancer risk. As such, there are no intake guidelines for grilled meat.
Still, it’s wise to reduce your exposure to HCAs and PAHs.
Choose lean cuts of meat. Grill small cuts of meat to reduce the time meat spends on the hot grill.
Marinating meat for at least 30 minutes before grilling can also inhibit HCA and PAH formation, thanks to antioxidants in marinade ingredients (herbs, spices, citrus juice, wine).
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
