Like many common food faux pax, most of us kind of know that sodas are bad for us… but we drink them anyway because we don’t really know why they’re bad. Here’s why.

(You now have no more excuses. You’re welcome.)

1. Sodas are the biggest source of calories in the American diet.

Want to lose weight? Cut out the soda. Regular sodas can have up to 50-80 grams of sugar per can.  (Context: a regular size Snickers bar has 30 grams!) While adults get about 7% of their calories from soda, teenagers get some13% from soda.

Why this is bad: Sugar is your enemy for a number of reasons. Sugar, not fat, is responsible for obesity. (If you don’t believe me, read this article). Childhood obesity has more than doubled in children and tripled in teens in the last 30 years – in 2010, more than 1/3 of children and teens were either overweight or obese, and Type 2 Diabetes (formerly referred to as “adult onset,” heavily linked to obesity) has become increasingly frequent in teens and children as well.

High Fructose Corn Syrup, one of the most common sweeteners in sodas, is especially nasty. While the body gets to choose whether it wants to use glucose (regular sugar) for energy or store it for future use (as fat), fructose bypasses this regulatory step and goes straight to fat. This means that it increases BMI and triglycerides, but doesn’t curb your appetite at all. It’s also six times as sweet as regular sugar — so in a sense, it “spoils” your taste for good, natural food.

Down the line, excess sugar also sets you up for heart disease, fatty liver disease and of course, diabetes.

Possible relationship to ADHD symptoms: a huge influx of sugar requires a huge output of insulin, which then leads to an equally fast sugar crash. The resulting hypoglycemia (low blood sugar) symptoms include shakiness, irritability, low energy and attention span, and sugar craving (so it perpetuates the cycle of poor food choices).

Sugar is also the primary food for the intestinal organism candida. If you eat a lot of sugar over a long enough period of time, and/or if you also have a poor gut flora balance to begin with, you may end up with candida overgrowth, one of the symptoms of which is brain fog and poor memory and concentration. (So we REALLY shouldn’t be selling this in school vending machines. That’s my $0.02.)

2. Massive amounts of sugar substitutes.

People think they’re being “good” by choosing the diet versions, which instead include artificial sweeteners such as Splenda (sucralose), Equal or NutraSweet (aspartame), and Sweet ’N Low (saccharin). But collectively these chemicals are associated with leukemia, brain tumors, breast cancer, bladder cancer, uterine and ovarian cancer, skin cancer, immune dysfunction, DNA damage, preterm delivery, and neurological problems.

Personally I’d rather be overweight and inattentive. (However, for some reason people who drink diet sodas are statistically even heavier than those who drink regular sodas — but so far no causal link has been established.)

3. Artificial colors and flavors.

These include caramel coloring, potassium benzoate, and food coloring.

Caramel coloring is produced by heating sugar with ammonia or ammonium compounds, and it’s potentially carcinogenic (cancer-causing).

Benzoates are used as preservatives. Some beverages also contain ascorbic acid (Vitamin C), in which case the two react to form small amounts of benzene — a known carcinogen.

Food dyes are collectively associated with allergies, brain tumors, bladder and testicular cancer, thyroid tumors, adrenal tumors, kidney tumors, ADD/ADHD and hypersensitivity reactions. The connection between Yellow #5 (aka tartrazine — think Mountain Dew) and ADD/ADHD is especially strong.

4. Strips your body, and your bones, of essential nutrients.

Phosphoric acid is an additive in sodas that gives it a “tangy” flavor, and makes it very acidic. Your blood, however, has to maintain a very specific pH… and if you ingest something very acidic, it has to “buffer” that acidity with minerals, which it strips from your bones. This can set you up for osteoporosis.

5. Caffeine. 

Although a little caffeine isn’t necessarily bad, too much definitely is. Caffeine doesn’t directly increase adrenaline, but it does allow it to work unhindered.  This can mean increased blood pressure, heart rate, palpitations, blood flow to the muscles, irritability and/or anxiety, as well as decreased blood flow to the brain. This, again, can contribute to impaired concentration and focus if you overdo it.

Too much caffeine can also contribute to adrenal fatigue, and weakened adrenals can lead to a whole host of problems. Depending on how exhausted you are, consuming caffeine to keep going is sort of like whipping a dead horse.

So skip the soda. Instead choose water, unsweetened tea (or sweetened with stevia, a little bit of honey, or even real cane sugar as long as you don’t go to town with it), small amounts of coffee (a little won’t hurt most of you), diluted fruit juice (to cut the sugar concentration), or — my favorite — carbonated flavored water.