The Science of Hunger, And How To Sate It

This is Dr. David Ludwig. That’s not a typo; he’s a doctor both ways—MD and PhD.

Henceforth we’ll just say “Dr. Ludwig”, though! He’s a professor in the Department of Nutrition at Harvard T.H. Chan School of Public Health, and director of the New Balance Foundation Obesity Prevention Center.

His research focuses on the effects of diet on hormones, metabolism, and body weight, and he’s one of the foremost experts when it comes to carbohydrates, glycemic load, and obesity.

Why are we putting on weight? What are we getting wrong?

Contrary to popular belief, Dr. Ludwig says, weight gain is not caused by a lack of exercise. In fact, people tend to overestimate how many calories are burned by exercise.

A spoonful of sugar may make the medicine go down, but it also contains 60 calories, and that’d take about 1,500 steps for the average person to burn off. Let’s put this another way:

If you walk 10,000 steps per day, that will burn off 400 calories. Still think you can exercise away that ice cream sundae or plate of fries?

Wait, this is interesting and all, but what does this have to do with hunger?

Why we get hungry

Two important things:

• All that exercise makes us hungry, because the more we exercise, the more the body speeds up our metabolism accordingly.
• Empty calories don’t just add weight themselves, they also make us hungrier

What are empty calories, and why do they make us hungrier?

Empty calories are calories that are relatively devoid of other nutrition. This especially means simple sugars (especially refined sugar), white flour and white flour products (quick-release starches), and processed seed oils (e.g. canola, sunflower, and friends).

They zip straight into our bloodstream, and our body sends out an army of insulin to deal with the blood sugar spike. And… that backfires.

Imagine a person whose house is a terrible mess, and they have a date coming over in half an hour.

They’re going to zoom around tidying, but they’re going to stuff things out of sight as quickly and easily as possible, rather than, say, sit down and Marie Kondo the place.

But superficially, they got the job done really quickly!

Insulin does similarly when overwhelmed by a blood sugar spike like that.

So, it stores everything as fat as quickly as possible, and whew, the pancreas needs a break now after all that exertion, and the blood is nice and free from blood sugars.

Wait, the blood is what now?

The body notices the low blood sugar levels, and it also knows you just stored fat so you must be preparing for starvation, and now the low blood sugar levels indicate starvation is upon us. Quick, we must find food if we want to survive! So it sends a hunger signal to make sure you don’t let the body starve.

You make a quick snack, and the cycle repeats.

Dr. Ludwig’s solution:

First, we need to break out of that cycle, and that includes calming down our insulin response (and thus rebuilding our insulin sensitivity, as our bodies will have become desensitized, after the equivalent of an air-raid siren every 40 minutes or so).

How to do that?

First, cut out the really bad things that we mentioned above.

Next: cut healthy carbs too—we’re talking unprocessed grains here, legumes as well, and also starchy vegetables (root vegetables etc). Don’t worry, this will be just for a short while.

The trick here is that we are resensitizing our bodies to insulin.

Keep this up for even just a week, and then gradually reintroduce the healthier carbs. Unprocessed grains are better than root vegetables, as are legumes.

You’re not going to reintroduce the sugars, white flour, canola oil, etc. You don’t have to be a puritan, and if you go to a restaurant you won’t undo all your work if you have a small portion of fries. But it’s not going to be a part of your general diet.

Other tips from Dr. Ludwig:

• Get plenty of high-quality protein—it’s good for you and suppresses your appetite
• Shop for success—make sure you keep your kitchen stocked with healthy easy snack food
• Nuts, cacao nibs, and healthy seeds will be your best friends and allies here
• Make things easy—buy pre-chopped vegetables, for example, so when you’re hungry, you don’t have to wait longer (and work more) to eat something healthy
• Do what you can to reduce stress, and also eat mindfully (that means paying attention to each mouthful, rather than wolfing something down while multitasking)

If you’d like to know more about Dr. Ludwig and his work, you can check out his website for coaching, recipes, meal plans, his blog, and other resources!

The Best-Laid Schemes of Mice and Medical Researchers…

This is Dr. Ellen Heber-Katz. She’s an internationally-renowned immunologist and regeneration biologist, but her perhaps greatest discovery was accidental.

Unlike in Robert Burns’ famous poem, this one has a happy ending!

But it did involve the best-laid schemes of mice and medical researchers, and how they did indeed “gang gagly“ (or in the English translation, “go awry”).

How it started…

Back in 1995, she was conducting autoimmune research, and doing a mouse study. Her post-doc assistant was assigned to punch holes in the ears of mice that had received an experimental treatment, to distinguish them from the control group.

However, when the mice were later checked, none of them had holes (nor even any indication there ever had been holes punched)—the experiment was ruined, though the post-doc swore she did her job correctly.

So, they had to start from scratch in the new year, but again, a second batch of mice repeated the trick. No holes, no wounds, no scarring, not disruption to their fur, no damage to the cartilage that had been punched through.

In a turn of events worthy of a superhero origin story, they discovered that their laboratory-made autoimmune disease had accidentally given the mice super-healing powers of regeneration.

In the animal kingdom, this is akin to a salamander growing a new tail, but it’s not something usually found in mammals.

Read: A New Murine Model for Mammalian Wound Repair and Regeneration

How it’s going…

Dr. Heber-Katz and colleagues took another 20 years of work to isolate hypoxia-inducible factor-1a (HIF-1a) as a critical molecule that, if blocked, would eliminate the regenerative response.

Further, a drug (which they went on to patent), 1,4-dihydrophenonthrolin-4-one-3-carboxylic acid (1,4-DPCA), chemically induced this regenerative power:

See: Drug-induced regeneration in adult mice

Another 5 years later, they found that this same drug can be used to stimulate the regrowth of bones, too:

An injectable hydrogel-formulated inhibitor of prolyl-4-hydroxylase promotes T regulatory cell recruitment and enhances alveolar bone regeneration during resolution of experimental periodontitis

And now…

The research is continuing. Here’s the latest, a little over a month ago:

Epithelial–mesenchymal transition: an organizing principle of mammalian regeneration

Regrowing nerves has also been added into the list of things the drug can do.

What about humans?

Superpowered mice are all very well and good, but when can we expect this in humans?

The next step is testing the drug in larger animals, which she hopes to do next year, followed eventually by studies in humans.

Read the latest:

Regrowing nerves and healing without scars? A scientist’s career-long quest comes closer to fruition

Very promising!