We pine for sweet. We have Sweetest Day. We send chocolates for Valentines Day. Poets coo about “lips sweeter than wine.” We have our sweethearts and our honeys. Beware poison that is sweet, for we will surely reach for it.

Why sweet? And why can't we lose weight by drinking sweet diet soft drinks? I love you, sweet, why do you curse me? Diet drinks and weight, what do you know?

T or F? 1. Diet Coke is the most popular soft drink worldwide. 2. Artificial sweeteners are as sweet as table sugar. 3. Aspartame is the most common artificial sweetener.

When Coca-Cola introduced Diet Coke in 1982 it quickly became a market leader. Today it ranks second behind Coke among the most consumed soft drinks in the world. Diet Pepsi, Diet Mountain Dew and Diet Dr. Pepper rank seventh, eighth and ninth respectively. They all contain artificial sweeteners.

The most commonly used artificial sweetener in soft drinks is aspartame (Equal, NutraSweet). It is a combination of 2 amino acids, the building blocks for protein, and is 200 times sweeter than table sugar (sucrose). Others added to drinks include saccharine, synthesized in 1879, sacralose (Splenda) and acesulfame potassium. All are sweeter than sucrose and none provide calories or fuel to the body.

Our primitive brains are programmed to seek out sweet. If given a choice, infants will choose sweeter substances over the sugar in breast milk. We humans are able to detect sweet, associated with energy, more readily than bitter, which is associated with poison. We gravitate to sweet energy-rich food and away from bitter, poisonous food, thereby improving our chances for survival. We are hard-wired for sweet.

Food scientists understand this primitive drive and create artificial substitutes so sweet and desirable we can't resist. Come to mommy. Historically pitched as integral to weight maintenance or loss, new evidence indicates that diet soda may actually promote weight gain. It is the dietary wolf in sheep's clothing.

Folks who are overweight and obese are more likely to consume diet drinks compared with normal weight individuals, indicating a desire to reduce calorie intake. Unfortunately, this strategy seems to backfire. In a recent study, those overweight and obese who consumed diet soda took in an average of 88 and 194 more calories daily than their sugar-drinking peers.

So why do we eat more when we drink diet soda? Emerging evidence suggests that artificial sweeteners cause sugar cravings. It seems that the brain and body, having been alerted to the promise of sugar by the artificially sweetened drink, prepare for a jolt of calories or fuel. But the fuel does not come and the brain and body react to this betrayal by unleashing a metabolic storm that causes sugar craving. The reduction in calories from diet soda is more than offset by those gained from eating more. We drink diet soda. We eat more sugary food. We gain weight. It is a vicious cycle. Voila. We are the most overweight and obese nation in the industrialized world.

Those reaching for diet drinks as part of a weight loss program need to understand this and make adjustments in the type and amount of solid food consumed.

We are learning it is hard to outsmart our primitive brain and circumvent our natural tendencies for sweet. We consumers and the diet soda industry are being reminded, “It's not nice to fool Mother Nature.” Diet soda is making regular soda, with its high fructose corn syrup, look like a health food. Maybe water is not so bad after all.

Answers: 1. F; 2. F; 3. T.

Dr. Lori Boyajian-O’Neill can be contacted at lori.boyajian-oneill@hcahealthcare.com.