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 Brain-Gut Two-Way Highway

This is Dr. Emeran Mayer. He has the rather niche dual specialty of being a gastroenterologist and a neurologist. He has published over 353 peer reviewed scientific articles, and he’s a professor in the Departments of Medicine, Physiology, and Psychiatry at UCLA. Much of his work has been pioneering medical research into gut-brain interactions.

We know the brain and gut are connected. What else does he want us to know?

First, that it is a two-way interaction. It’s about 90% “gut tells the brain things”, but it’s also 10% “brain tells the gut things”, and that 10% can make more like a 20% difference, if for example we look at the swing between “brain using that 10% communication to tell gut to do things worse” or “brain using that 10% communication to tell gut to do things better”, vs the midpoint null hypothesis of “what the gut would be doing with no direction from the brain”.

For example, if we are experiencing unmanaged chronic stress, that is going to tell our gut to do things that had an evolutionary advantage 20,000–200,000 years ago. Those things will not help us now. We do not need cortisol highs and adrenal dumping because we ate a piece of bread while stressed.

Read more (by Dr. Mayer): The Stress That Evolution Has Not Prepared Us For

With this in mind, if we want to look after our gut, then we can start before we even put anything in our mouths. Dr. Mayer recommends managing stress, anxiety, and depression from the head downwards as well as from the gut upwards.

Here’s what we at 10almonds have written previously on how to manage those things:

• No-Frills, Evidence-Based Mindfulness
• How To Set Anxiety Aside
• The Mental Health First-Aid You’ll Hopefully Never Need

Do eat for gut health! Yes, even if…

Unsurprisingly, Dr. Mayer advocates for a gut-friendly, anti-inflammatory diet. We’ve written about these things before:

• Making Friends With Your Gut (You Can Thank Us Later)
• Keep Inflammation At Bay

…but there’s just one problem:

For some people, such as with IBS, Crohn’s, and colitis, the Mediterranean diet that we (10almonds and Dr. Mayer) generally advocate for, is inaccessible. If you (if you have those conditions) eat as we describe, a combination of the fiber in many vegetables and the FODMAPs* in many fruits, will give you a very bad time indeed.

*Fermentable Oligo-, Di-, Monosaccharides And Polyols

Dr. Mayer has the answer to this riddle, and he’s not just guessing; he and his team did science to it. In a study with hundreds of participants, he measured what happened with adherence (or not) to the Mediterranean diet (or modified Mediterranean diet) (or not), in participants with IBS (or not).

The results and conclusions from that study included:

❝Among IBS participants, a higher consumption of fruits, vegetables, sugar, and butter was associated with a greater severity of IBS symptoms. Multivariate analysis identified several Mediterranean Diet foods to be associated with increased IBS symptoms.

A higher adherence to symptom-modified Mediterranean Diet was associated with a lower abundance of potentially harmful Faecalitalea, Streptococcus, and Intestinibacter, and higher abundance of potentially beneficial Holdemanella from the Firmicutes phylum.

A standard Mediterranean Diet was not associated with IBS symptom severity, although certain Mediterranean Diet foods were associated with increased IBS symptoms. Our study suggests that standard Mediterranean Diet may not be suitable for all patients with IBS and likely needs to be personalized in those with increased symptoms.❞

In graphical form:

And if you’d like to read more about this (along with more details on which specific foods to include or exclude to get these results), you can do so…

• The study itself (full article): The Association Between a Mediterranean Diet and Symptoms of Irritable Bowel Syndrome
• Dr. Mayer’s blog (lay explanation): The Benefits of a Modified Mediterranean Diet for Irritable Bowel Syndrome

Want to know more?

Dr. Mayer offers many resources, including a blog, books, recipes, podcasts, and even a YouTube channel: