by Thomas Rutledge Ph.D.

Metabolic biology meets food psychology.

Key points

• Food cravings are a frequent negative experience for many people.
• Although commonly thought of as psychological, many food cravings may be biologically based.
• Recent research using continuous glucose monitors shows that glucose variation predicts food cravings.
• Tracking and reducing blood glucose variation may help reduce food cravings.

For tens of millions of Americans, food cravings are a frequent or even daily experience. Defined as “an intense desire to consume a particular food,” cravings are not just harmless feelings. Instead, for the people who struggle with them, food cravings produce a host of adverse consequences.¹ These consequences include the psychological, such as emotional distress and compulsive eating, and the physical in the form of conditions such as diabetes, obesity, and metabolic-associated liver disease.²

With food cravings concurrently so common and so counterproductive to quality living, it is no surprise that an entire industry exists to treat them. From the self-help economy to licensed nutritionists and psychologists, there is seemingly a bestselling book, five-star podcast, website resource, or professional treatment for everyone. But if that were true, shouldn’t food cravings and related food addiction behaviors be declining, instead of still on the rise as suggested by recent research?³ Something must be missing.

Here is a simple, science-based explanation for food cravings that offers an equally simple remedy for people who struggle with them.

All it requires is mastering some basic information about your blood glucose.

Basics about blood glucose

Without blood glucose, also called “blood sugar” in casual circles, there is no life. It is that important. Blood glucose is so crucial to life that your body can make it (in a process called gluconeogenesis) in the absence of food. Gluconeogenesis is why you can go days or even weeks without food while still maintaining a normal blood glucose level.

Blood glucose, however, is also like fire. The right amount of blood glucose keeps your metabolic engine burning. But either too little (hypoglycemia) or too much (hyperglycemia or diabetes when chronic) quickly becomes dangerous.

Although many people have heard of high blood glucose in the context of pre-diabetes or diabetes, fewer know about blood glucose variability. This is a major knowledge gap because research increasingly shows that blood glucose variability may cause food craving symptoms even among people with healthy average blood glucose levels (that is, people without diabetes).⁴

The best way to understand blood glucose variability is with a chart like the one here.

The above shows the blood glucose patterns for two hypothetical people eating breakfast. Notice on the left-hand side of the graph that each person has a healthy baseline blood glucose level of 100 mg/dL before eating. However, Person 1 (blue line), shows only a small increase in their blood glucose levels after eating and a return to their baseline levels with 60-90 minutes after their meal. This is an example of “low blood glucose variability”. It promotes stable mood, energy levels, and good cognitive function. This person is also unlikely to experience food cravings with this blood glucose variability pattern.

Person 2 (orange line), in contrast, shows a high level of blood glucose variability (notice the high post-meal increase in blood glucose and the “crash” below baseline levels afterward). A person with this pattern of blood glucose variability is much more likely to experience food cravings, fatigue, and negative affect based on research.

The question is how do you know if you’re more like Person 1 or Person 2 in the above graph?

Understanding your individual blood glucose profile

The classic study on this topic was published in the prestigious medical journal, Cell, in 2015.⁵ Before this study, most people thought that blood glucose responses to food could be accurately predicted using the glycemic index. The glycemic index is only accurate when averaged across many people. The same index can be surprisingly inaccurate for individuals.

The Cell researchers used wearable technology called continuous glucose monitoring (CGMs) to study individual food responses. Even they were stunned by how much people differed. Some people in the study, for example, could eat a sugary breakfast cereal or ice cream and show minimal blood glucose increases. Meanwhile, others could eat plain oatmeal and see large blood glucose spikes (you can find a short and entertaining video summary of the study on YouTube).⁶ 

Without using a CGM, there was simply no way for a person to know how much their blood glucose was changing from the foods they ate. But, as subsequent CGM research showed, energy levels, emotions, and food cravings are important clues about what is happening inside our metabolic system.

Addressing Healthcare Disparities in the Black Community

A full decade after this famous 2015 Cell study, CGMs are now available over the counter without a prescription. A person struggling with food cravings in 2025 is now even likely to receive a recommendation from a nutritionist or health psychologist to trial a CGM for a few weeks (along with keeping a nutrition diary) as part of their treatment. This approach can reveal previously invisible but powerful connections between food choices, eating patterns, blood glucose responses, and food craving symptoms. As important, this approach can identify personalized changes that can reduce the frequency and intensity of food craving symptoms for many people.