Women who are pregnant would benefit from focusing more attention on their nutrition, for a Japanese study has uncovered what may be a real link between childhood obesity and undernourished pregnant mothers: An extra surge of the fat hormone leptin, which normally decreases food intake while increasing energy output.

In order to determine if leptin is indeed a culprit, researchers compared two sets of pregnant mice -- one underfed and the other fed a normal diet.

Mice Studies

As in previous studies, underfed pregnant mothers gave birth to lower weight mice that grew quickly and caught up with normal pups after 10 days; when fed an average diet after weaning, pups from both normally and underfed mothers weighed the same and had similar fat reserves.

However, when mice from malnourished mothers were fed a high-fat diet, they grew much bigger than those born from mothers who were fed an average diet. In fact:

• At 17 weeks, the underfed group weighed about 15 percent more and stored 50 percent more fat than the prenatally well-nourished mice on the same high-fat diet.

• Also, underfed pups showed a premature surge in leptin levels at 8-10 days old, compared with a surge on day 16 in normal pups.

How does this extra leptin change the obesity cycle? An early leptin spike modifies neural circuitry during a critical stage in development and interferes with the transport of leptin to the brain in adulthood -- making mice far less sensitive to feeling full.

These findings, according to experts, underpin the importance of a balanced, nutritional diet during pregnancy.

Cell Metabolism June 2005, Vol. 1: 371-378

New Scientist June 7, 2005

Guest Comment by Dr. Rosedale:

A very important concept to understand is that eating fat does not make you fat. It is the inability to burn fat that will make you fat and be a fundamental factor in the causation of the chronic diseases of aging including obesity, diabetes, heart disease, autoimmune diseases, arthritis, osteoporosis and perhaps even the rate of aging itself.

The ability to burn fat or not is regulated by very powerful and influential hormones, and it appears the most significant of these is leptin. In this study, and in a couple of other recent studies, elevated leptin has been shown to be able to actually rewire the architecture of critical areas (in the hypothalamus) of the brain in the fetal stage, and even later as an adult in certain animals.

In other words, excess leptin can change your brain. When you, and especially your brain, cannot properly understand the critical messages that leptin is trying to convey, your body does not know how to handle its energy resources and that is a recipe for disaster.

In the conclusion of the present study is a very revealing statement, and I will quote it here:

"This study also highlights the leptin surge as a target for therapeutic intervention in the developmental origins of health and disease."

The importance of surges in leptin in the "developmental origins of health and disease" is emphasized. I myself cannot emphasize that enough. I believe that there is no other statement in health quite as powerful as that sentence.

If you eat a diet (and most of us do) that causes surges in leptin, you will cause disease -- virtually all of the chronic diseases of aging, most notably diabetes, heart disease, obesity, and accelerated aging itself. There are no drugs that can therapeutically intervene in reducing leptin levels; however, eating a diet such as that outlined in my book The Rosedale Diet or in Dr. Mercola's Total Health Program can powerfully and quickly reduce surges in leptin and leptin resistance.

You will be taking a giant step in reestablishing your body's ability to hear the vital messages that leptin is sending you about whether to store or burn fat and, indeed, how to use that energy to stay alive and healthy.

Related Articles:

Leptin: How Diabetes and Obesity Are Linked

What You Don't Know About Leptin Can Make You Fat

Protein Possible Key to Obesity Hormone's Effect on Brain