If you've been told that managing your weight—and by extension, your diabetes risk—is simply a matter of eating less and moving more, you're not alone. This advice has dominated nutrition guidance for decades. But what if the story is more complicated? What if the types of foods you eat trigger hormonal cascades that fundamentally change how your body stores and burns energy?
Two competing scientific models are currently battling to explain why we gain weight and develop metabolic diseases like type 2 diabetes. Understanding these frameworks can help you make better sense of conflicting dietary advice and empower you to take control of your metabolic health.
The Traditional View: The Energy Balance Model
The Energy Balance Model (EBM) has been the cornerstone of nutrition science since the 1950s. Built on the fundamental principle of energy conservation, it states something seemingly obvious: you gain weight when you consume more calories than you burn, and you lose weight when you burn more than you consume.
This model makes intuitive sense. If your body is like a bank account, calories are deposits and physical activity represents withdrawals. Spend more than you deposit, and your balance goes down. Simple, right?
But modern proponents of the EBM acknowledge it's not quite that simple. The updated version recognizes that different types of calories have different metabolic effects. A hundred calories from refined sugar doesn't affect your body the same way as a hundred calories from lean chicken breast. Protein requires more energy to digest and keeps you feeling full longer, while refined carbohydrates can spike your blood sugar and leave you hungry soon after eating.
What the Energy Balance Model Gets Right
Research supporting the EBM has identified several important factors in weight gain:
Ultra-processed foods are a major culprit: These engineered foods—think chips, cookies, frozen meals, and sugary drinks—may activate brain reward centers similarly to addictive substances. They're designed to be hyper-palatable, making it easy to overeat without realizing it.
The gut-brain connection matters: Your gut communicates with your brain in ways that influence eating behavior, sometimes unconsciously. Hormones released from your digestive system signal fullness or hunger, affecting how much you eat.
Calorie quantity matters: Multiple studies show that when total calories are controlled, high-carb/low-fat diets and low-carb/high-fat diets produce similar weight loss results.
Where the Energy Balance Model Falls Short
Despite its scientific basis, the EBM has significant limitations:
First and most obviously, the "eat less, move more" approach hasn't solved the obesity epidemic. If the solution were truly that straightforward, why do obesity and type 2 diabetes rates continue climbing globally?
Second, the model doesn't adequately explain the biological mechanisms that cause weight regulation to go haywire. Why do some people seem to effortlessly maintain a healthy weight while others struggle despite their best efforts? Why does weight loss become progressively harder over time?
Critics also point out that many feeding studies supporting the EBM are too short to reveal meaningful long-term results. A two-week metabolic ward study may show one thing, but what happens over months or years of real-world eating?
The Challenger: The Carbohydrate-Insulin Model
Enter the Carbohydrate-Insulin Model (CIM), which flips the conventional wisdom on its head. Instead of saying "overeating causes weight gain," the CIM proposes that "gaining weight causes overeating."
This might sound backward at first, but here's the core argument: When you eat high-glycemic foods (refined carbohydrates that quickly spike blood sugar), your body releases a surge of insulin. Insulin is a storage hormone—it tells your cells to take up glucose from your bloodstream and signals fat cells to store energy.
According to the CIM, this insulin spike creates what proponents call a "calorie distribution problem." Instead of calories remaining available in your bloodstream to fuel your body's energy needs, they get siphoned into fat tissue and locked away. Your fat cells are growing, but the rest of your body thinks it's starving, triggering hunger and fatigue. You eat more not because you lack willpower, but because your body genuinely needs energy that's been inappropriately stored away.
How This Relates to Diabetes
For people with diabetes or prediabetes, this model has particular relevance. When insulin levels are chronically elevated—either because you're eating high-glycemic foods frequently or because your cells have become insulin resistant—your body cannot effectively burn stored fat. You're stuck in storage mode.
This creates a vicious cycle: high insulin prevents fat burning, leading to weight gain and further insulin resistance, which requires even more insulin to manage blood sugar, leading to more fat storage. Eventually, your pancreas can't keep up with the insulin demand, and blood sugar rises into the diabetic range.
The Evidence Supporting the Carbohydrate-Insulin Model
Proponents of the CIM point to several lines of evidence:
Some research suggests that low-carbohydrate, high-fat diets may result in more weight loss than high-carb diets over the long term, even when calories aren't strictly controlled.
The model explains why low-carb diets often improve blood sugar control in people with type 2 diabetes—by reducing the insulin response, they allow fat burning to resume.
It accounts for why calorie restriction often fails—if you cut calories while still eating high-glycemic foods, you're fighting against your hormones.
Serious Challenges to the Carbohydrate-Insulin Model
Despite its appeal, the CIM faces substantial scientific criticism:
Many populations with traditionally high-carbohydrate diets—like the Kitavans of Papua New Guinea or the Japanese—have historically low rates of obesity and diabetes. If carbohydrates were the primary driver, these populations should be struggling with weight.
Controlled studies comparing low-glycemic and high-glycemic diets show minimal differences in long-term weight loss, contradicting a key CIM prediction.
Perhaps most damaging, carefully controlled mouse studies directly refute the core premise. Mice fed high-glycemic diets actually ate fewer calories and gained less weight than predicted, despite having higher insulin levels.
The CIM predicts a "dynamic phase" of obesity where blood glucose and free fatty acids in the blood should be reduced as calories get trapped in fat tissue. This phase has never been observed in humans.
Recent genetic research shows that genes associated with obesity are more strongly linked to neurological development and brain function than to insulin signaling or fat cell function, suggesting that appetite regulation in the brain may be more fundamental than hormonal fat storage.
Where Both Models Agree—And What That Means for You
Interestingly, as research continues, the two camps have been moving closer together. Both now acknowledge that the amount of calories you eat and the types of foods providing those calories likely both matter.
More importantly for people concerned about diabetes and weight management, both models agree on several practical points:
Avoid ultra-processed foods: Whether they cause problems by delivering too many easy calories or by triggering excessive insulin responses, highly processed foods are detrimental to metabolic health.
Eat for stable blood sugar: Even proponents of the EBM acknowledge that foods causing large blood sugar spikes can lead to hunger and overeating. Managing your blood glucose matters regardless of which model is ultimately correct.
Prioritize whole foods: Vegetables, fruits, legumes, whole grains, lean proteins, and healthy fats form the foundation of both approaches.
Consider your individual response: Some people feel and function better on lower-carb diets, while others thrive with more carbohydrates. Pay attention to how different foods affect your energy, hunger, and blood sugar.
Don't forget lifestyle factors: Both models recognize that exercise, adequate sleep, and stress management are crucial for metabolic health. These factors affect both calorie balance and hormonal regulation.
The Bottom Line: What Science Still Needs to Figure Out
The honest truth is that the science of obesity and metabolic disease remains largely unresolved. Leading researchers on both sides acknowledge significant gaps in our understanding.
Dr. Kevin Hall, a prominent EBM researcher, advocates for more mechanistic research to understand precisely how different foods and eating patterns affect our biology. Dr. David Ludwig, a leading CIM proponent, calls for longer, better-funded trials of low-carbohydrate diets to properly test the model's predictions.
What does this scientific uncertainty mean for you? It means that dogmatic claims from any side should be viewed with skepticism. It means that individual experimentation, guided by your healthcare team, is reasonable. And it means that focusing on fundamentals—whole foods, stable blood sugar, regular physical activity, quality sleep, and stress management—remains your best strategy.
Practical Takeaways for Managing Diabetes and Weight
While scientists continue debating the mechanisms, here's what you can implement today:
Monitor your blood sugar response: If you have diabetes or prediabetes, checking your blood glucose after meals can reveal which foods cause problematic spikes for you personally.
Reduce refined carbohydrates: Regardless of which model is correct, minimizing white bread, white rice, sugary drinks, and sweets will benefit your metabolic health.
Focus on fiber: High-fiber foods slow glucose absorption, promote feelings of fullness, and feed beneficial gut bacteria—addressing concerns of both models.
Include adequate protein: Protein helps preserve muscle mass during weight loss, requires more energy to digest, and promotes satiety.
Be mindful of portions: Even healthy foods contribute calories. Pay attention to hunger and fullness cues.
Move regularly: Physical activity improves insulin sensitivity, burns calories, and provides numerous other health benefits.
Prioritize sleep: Poor sleep disrupts hunger hormones and glucose metabolism, increasing diabetes and obesity risk regardless of your diet.
The debate between these models reminds us that human metabolism is extraordinarily complex. Rather than waiting for science to deliver a final verdict, focus on the principles where evidence converges: eat whole foods, manage your blood sugar, stay active, sleep well, and minimize stress. These fundamentals support optimal metabolic health regardless of which model ultimately proves more accurate.
References
Hall, K. D., & Guo, J. (2017). Obesity Energetics: Body Weight Regulation and the Effects of Diet Composition. Gastroenterology, 152(7), 1718-1727. doi:10.1053/j.gastro.2017.01.052
Ludwig, D. S., & Ebbeling, C. B. (2018). The Carbohydrate-Insulin Model of Obesity: Beyond 'Calories In, Calories Out'. JAMA Internal Medicine, 178(8), 1098-1103. doi:10.1001/jamainternmed.2018.2933
