We know insulin resistance contributes to Type 2 diabetes. But resistance to another hormone called leptin also contributes big time. Fortunately, we may be able to turn down both kinds of resistance.
Leptin helps regulate body fat, in part by telling the brain what level of fat is in the body and how that level is changing. When fat stores are sufficient, it lets the brain know, “We’re full. We have enough food now. So stop eating.”
Some Indian scientists put it in more technical terms: “The net action of leptin is to inhibit appetite, stimulate thermogenesis [heat production], [burn up fatty acids], decrease glucose, and reduce body weight and fat.”
Those are good things for most of us. We want that. But many people, especially overweight people, are leptin resistant. Talking to the UK newspaper Daily Mail, anti-sugar crusader Robert Lustig, MD, said, “This means the…brain…no longer ‘reads’ the signals saying the body is full, but instead assumes it is starving — no matter how much food you continue to eat.”
So leptin resistance (LR) contributes to fatness in much the same way that insulin resistance (IR) contributes to Type 2 diabetes. In fact, the two frequently go together. Not always — as we know, most overweight people don’t have diabetes, and many people with Type 2 are thin. But a huge number of people have both types of resistance, which is why overweight people are more likely to get diabetes, and diabetes gets wrongly blamed on fat.
In fact, Dr. Lustig believes insulin resistance triggers LR. Insulin blocks leptin’s fullness signals in the brain.
His studies have found that lowering insulin levels stops cravings and helps people get control of their food consumption, presumably because leptin is working again.
Scientists used to think increasing leptin levels would allow people to control their eating and their weight. You can buy leptin supplements in health food stores, but they don’t help. Overweight people actually tend to have more leptin than thin people. In a similar way, people with prediabetes tend to have higher than normal levels of insulin. That’s one way you become resistant in the first place. When there’s too much insulin or leptin around all the time, the body starts to tune it out.
What causes leptin resistance? Your genes are a big factor, but Dr. Lustig thinks it’s mainly sugar consumption. Sugar sets off a spike in insulin, which blocks leptin. That’s why insulin resistance and LR go together.
Many experts agree that diet is the problem. For example, Dr. Oz says eating “high-fructose corn syrup or lots of carbs,” causes LR. He advises eating lots of protein and fiber.
Dr. Joseph Mercola also says it’s the diet, especially “a diet that is high in sugar (particularly fructose), grains, and processed food.”
But there’s more to it than food. Dr. Oz also says that “if you’re very stressed or sleep deprived,” you are at risk.
To me, stress is a major culprit in leptin resistance, just as it is in insulin resistance. Leptin is an “all is well” hormone. It tells your body to relax, “We’ve got enough energy stored, don’t need anymore. In fact, go ahead and burn some for an extra lift. We’re OK.”
Kind of like God in the Book of Exodus, leptin is telling us not to collect more manna than we can eat in one day. “You don’t need any more. There will be more tomorrow.”
But stress is screaming “We’re not OK. We’re in danger here. Keep eating. Pack on all the fat you can.” Stress causes IR to help with fight or flight. It causes LR to build up stores of energy for coming hard times.
Diet and exercise are the main ways to reduce leptin resistance. But what kind of diet? Neurosurgeon and leptin expert Jack Kruse, MD, writes a lot about leptin on his blog Reversing Disease for Optimal Health. One interesting thing is that he says “the iming of when you eat is more important than what you eat… NO SNACKING! Snacking destroys timing and circadian clocks that work in unison with Leptin.”
Dr. Kruse and Dr. Mercola both say to eat few carbs. In general, most of the leptin writers seem to advocate a Paleo diet, meaning few or no grains or sugars.
Since an LR diet is similar to an insulin resistance diet, Mediterranean-style without refined grains and sugars, probably anyone with Type 2 should assume they have some LR and eat accordingly.
The first international web summit on reversing Type 2 diabetes is coming to a close. My interview will be aired on May 15 and will be available for 24 hours until 10 AM May 16. You can also order all 50 talks as part of a download package. Please go here to register. It’s free. Then scroll to the bottom and click on schedule and all the talks will come up. Many are fascinating, although most are about diet.