Chalkboard with “True or False?” written on it.
Chalkboard with “True or False?” written on it.
Image credit: ChristianChan.

The journal Science has published a short opinion essay on the “failure” of the Carbohydrate-Insulin Model of obesity (CIM) to explain the results of half a dozen experimental tests.

This brings to at least a dozen the number of dismissive opinions in recent years, many by one or both of the same authors (Speakman & Hall), based on the same collection of weak studies and disregard of nearly a century of supportive research.

For a description of the CIM, see this link. Below, I briefly address issues with the studies considered in the Science paper.

Animal Research

The 29-diet animal study by…

We reviewed over 100 studies and conclude that milk recommendations for Americans are not based in evidence

Photo: Jack Andersen/Getty Images

It’s perhaps the most widely advocated nutrition recommendation of the last half-century: For strong bones and overall health, consume three servings of reduced-fat milk a day.

The USDA’s “ChooseMyPlate” dedicates a corner of their icon for milk and equivalent dairy products (Figure 1).

Schools must offer fat-free or 1% low-fat milk at lunch and other meals. To get kids to drink it, the government allows chocolate and other sugary varieties — but not plain whole milk!

A new, major study supports the “Carbohydrate Insulin Model” of obesity

Illustration: PollyW/Getty

The Problem

Most people have trouble staying on a weight-loss program.
Of those who stay on a program, most don’t lose much weight.
Of those who do lose weight, most regain it in 1 or 2 years.

It’s now time to question every assumption.

The conventional approach to obesity considers weight control as a matter of accounting — too many calories into the body, not enough calories out. The solution: count calories, eat less and move more. As long as you have a negative “energy balance,” you’ll eventually solve the problem.


Our study in the journal Pediatrics is available here. An accompanying commentary (worth reading) is available here. And a NY Times article about our findings, with a patients’ perspective, is available here.

The biggest challenge facing people with any form of diabetes, and especially type 1 (“juvenile”), is controlling blood sugar around meals.

After eating a lot of carbohydrate, blood sugar rises rapidly for 1 or 2 hours. But the insulin needed to control that rise can cause low blood sugar later.

Despite the latest technologies for monitoring blood sugar and administering insulin, most people with type 1 diabetes mellitus…

A “Case Study” of Research on Sugar-Sweetened Beverages

The accompanying study in Public Health Nutrition is available here and a version of this blog is available here on the publisher’s website.

Numerous reviews of the scientific literature show that when a food company funds a nutrition study, the conclusions are much more likely to favor the sponsor’s financial interests than when the study is independently funded. This finding raises the possibility that research sponsored by the food industry might corrupt the scientific literature and undermine public health.

However, the associations between study sponsorship and outcomes cannot prove that industry-funding causes bias. Beyond financial relationships, other factors might in…

This article is adapted from my commentary in the journal Pediatrics, available here. The study on childhood obesity rates is available here.

After 35 years of unremittingly bad news about childhood obesity, national data from earlier this decade suggested a plateau in overall prevalence and a statistically significant decline among 2- to 5-year-olds. News reports in 2014 celebrated “the first clear evidence that America’s youngest children have turned a corner in the obesity epidemic.” Perhaps Michelle Obama’s Let’s Move campaign, Robert Wood Johnson Foundation’s $500 million prevention initiative, and growing public awareness had finally begun to pay off.

Unfortunately, this…

According to the Carbohydrate-Insulin Model of Obesity (CIM), the processed carbohydrates that flooded our diet during the low-fat diet craze undermine our metabolism and drive weight gain. Put simply:

  1. Processed carbohydrates — think white bread, white rice, potato products, low -fat snacks — raise insulin more than any other food, calorie for calorie. This is just Nutrition, 101.
  2. Insulin is the Miracle-Gro for your fat cells. A child with new onset type 1 diabetes — unable to make enough insulin — will invariable lose weight until receiving treatment, no matter how many calories she consumes. Give that child the right…

How long does it take for your body to become adapted to a low-carbohydrate diet? This question has relevance for everyone trying low-carbohydrate diets for weight loss, and also for a raging scientific controversy.

Some critics have pointed to studies lasting just a few days, as evidence that low-carbohydrate diets are detrimental to metabolism. But these studies have a fatal flaw, as it relates to long-term effects.

On a standard high-carbohydrate diet, the brain is critically dependent on glucose. So if you restrict carbohydrate in your diet (or you fast for more than a day), your body must initially break…

Chalkboard with “True or False?” written on it.
Chalkboard with “True or False?” written on it.

Is the Carbohydrate-Insulin Model Dead? The Rumors Have Been Exaggerated

A version of this post is available on PubMed, linked here.

In a new review, Kevin Hall claims to have “falsified” the Carbohydrate-Insulin Model (CIM) of obesity as iterated by Mark Friedman and me in 2014. Hall describes this achievement as “rare” in nutritional science, like refuting the “luminiferous ether” hypothesis of the 19th century. Elsewhere, he argues that the published data are so definitive as to warrant curtailment of further funding for macronutrient-focused obesity research.

To loosely paraphrase Mark Twain, rumors of CIM’s demise have been greatly exaggerated.


by Dr. David Ludwig

Today, it’s easier than ever before to get tasty food almost instantly. From drive-through restaurants to frozen dinners, we can satisfy virtually any craving without having to turn on the oven or go near the kitchen. Is all this tasty food to blame for our expanding waistlines?

Some notable public health experts and science writers have eloquently described how the food industry manipulates three basic flavors — sweet, fat, and salt — to make modern processed food virtually irresistible. These exceedingly tasty products, as the argument goes, overstimulate the pleasure circuits in the brain, leading to…

Dr. David Ludwig

Physician, Nutrition Researcher, and Public Health Advocate. #1 NY Times bestselling author ofALWAYS HUNGRY? and ALWAYS DELICIOUS

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