Lustig instead attributes the rise in obesity (increasing one percent every year) and other related health problems to the rise of sugary processed foods. His catchphrase—repeated throughout his lecture and his books— is that a calorie is not a calorie. Our body processes different types of fats and carbs in radically different ways. Take fat. There are good fats, like the omega-3 fatty acids (found in wild fish and flax,) and bad fats, like omega-6 fatty acid found in corn-fed beef. Omega-3s reduce inflammation and repair membranes, whereas omega-6s cause inflammation and increases risk of health problems like arthritis and cancer.

We Get Too Much...Photo: Wendy Goodfriend

The same goes for carbs. There are good carbs, like lactose, the sugar found in milk, or fiber-heavy foods like vegetables and whole grains. But the worst carb of all, says Lustig, is sugar. It’s omnipresent in our food supply (77% of the foods in the America food supply include added sugar), and plays a huge role in metabolic syndrome, which leads to diseases like diabetes: Lustig cited a study that showed while eating an extra 150 calories per day did not increase diabetes prevalence worldwide, if those calories came from soda, diabetes prevalence went up 11-fold for the same number of calories.

We Get Too Little...Photo: Wendy Goodfriend

The negative effects sugar has on our bodies are staggering: sugar alters our hormones so we don’t register hunger the way we normally would, making us eat more; it spikes our dopamine, making us requiring us to eat more sugar for the same effect; and it affects our liver in the same way that alcohol does. We consume an astounding 18 bags of sugar per year, and half of that is added sugar, hidden away in our ketchup and potato chips under names like brown rice syrup and fruit puree (last year, Lustig wrote an ebook called Sugar Has 56 Names: A Shopper's Guide). And even if we tried to cut down on sugar, food companies have every incentive to keep us from doing just that: sugar is a cheap preservative that extends food’s shelf life and keeps prices low.

Listening to Lustig’s lecture, it’s easy to feel powerless, or think back guiltily to the honey in your tea or the granola you ate with your yogurt this morning (“Granola,” Lustig said sternly, “is a dessert.”). Yet, there are things we can do to fix what Lustig calls our “toxic food environment.”

Dr. Robert Lustig's Toxic Clean-Up Tips. Photo: Wendy Goodfriend

The most valuable change, he says, is shifting your diet to one low in sugar and high in fiber. You don’t need to skip every birthday cake or break room muffin, but toss the soda and juice (which is just as bad as soda, according to Lustig) and start eating more vegetables and whole grains. Lustig cited the famous Michael Pollan maxim to “Eat food, not too much, mostly plants” but told the audience to focus on the first part of the sentence—focusing on eating real food, he said, the kind your grandmother would recognize, is the most efficient way to better health.

Lustig, a former college actor, has a flair for the dramatic. At the beginning of his lecture at KQED, he promised to “change your whole thinking about obesity, diets, and what really causes many of our most dangerous diseases.” It’s a bold claim, especially when we’re awash in diets all claiming to be the healthiest choice, with the high fat Paleo crowd competing against the low fat diet advocates (A debate which Lustig is ambivalent on: they’re both healthy, he said, but he has no preference for any particular diet as long as it’s high fiber, low sugar and free of processed foods.)

Yet, even if you’re one of the millions who watched Lustig’s original lecture, or you’ve read one of the countless articles about cutting your sugar intake, there’s still much to be gained from reading Lustig’s books, or watching his KQED lecture when it airs in October. Lustig has the ability to distill complex biological processes into simple explanations, the case studies from his work illuminate the misconceptions we have about obesity (it’s hard to argue that obesity is a personal choice when confronted with an obese six month old), and perhaps most importantly, the ability to inspire hope about an issue that often seems impossible to fix.

Dr. Robert LustigDr. Robert Lustig

Sweet Revenge: Dr. Robert Lustig Explains How to Cut Sugar, Lose Weight and Turn the Tables On Processed Foods

Can You Be Addicted To Carbs? Scientists Are Checking That Out

Sugar's Role In Rise Of Diabetes Gets Clearer

Edible Education 101: Sugar Is Not So Sweet After All