I would suggest reading all of this, however if you don't have the mind for the science behind Obesity, I suggest you look at the bold and underlined parts then skip to the bottom.
The MSG of Obesity:
Studies have been published about obesity in rats/mice who were injected/fed free glutamatic acid. These studies can also be very apparent in real-life human scenarios. As kids age and get older, the parents buy processed foods to feed them because they are convenient. Inside these processed foods are vast amounts of free glutamate used as "flavor enhancers". Even as a child who has just started eating baby food, they are already being exposed to a large amount of free form processed glutamic acids. Baby foods such as: Gerber "Good Start" Formula ["Enzymatically Hydrolyzed" Whey Protein Concentrate], Gerber Graduates Entrees [Natural Flavoring and Carageenan], and Beech Nut Baby Foods [Citric Acid w/Protein]). Baby food is not new to labeling problems and petitions.
As the child progresses, they're lured into the marketing fads of processed "fun" and "cool" drinks such as: Kool Aid Bursts [Natural and Artificial Flavoring], Kool Aid Drink Packets [Natural and Artificial Flavoring], Capri Sun Drinks [Natural and Artificial Flavoring], all of which have high fructose corn syrup in them as well as added citric or ascorbic acid and these are only a few examples. Is there a pattern here? Possibly, considering many kids grow up guzzling these down just before or after recess, many more during the rest of their day. If they wont drink water, we'll feed them Vita Water [Natural Flavoring]! Foods are no different;go ahead and look at some of the foods marketed directly towards children, Totino's Pizza Rolls for example which is loaded with many forms of free glutamate (Natural Flavoring, Maltodextrin, "Spice" and more Natural Flavoring [lol]). From this we conclude that 90%, if not 100% of kids' diet consists of consuming the excitotoxin Free Glutamic Acid.
How Free Glutamate makes kids fat:
Consuming free glutamate also increases the body's resistance to Leptin, which is the body's natural appetite suppressant and made by the body's own fat cells as a "nutrition inventory" signal. The increased resistance to Leptin comes from the mass amounts of free glutamate exciting and causing damage to the Hypothalamus, which is supposed to counteract the effects of "Neuropeptide Y (aka: NPY)" (appetite stimulant, produced by the body). NPY and Leptin are supposed to work synergistically to balance out the body fat in the body. When the Hypothalamus becomes resistant to Leptin due to damage from free glutamate, the body can no longer shut off it's appetite stimulant, thus the person eats MORE than they should. You would interpret all of this as "I'm still hungry".
This will be short (too much to type about AMPK). Leptin directly effects and suppresses AMPK (Activated Protein Kinase) which is an enzyme that essentially regulates nutrition storage in the body. In short, Leptin suppresses the effects of AMPK-in the brain. The effects of AMPK are: activating energy storing pathways and deactivating energy costing pathways. If the brain doesn't properly receive the signals regarding it's nutrition stores, it will remain in a energy storing state. Hence Leptin desensitivity leads to Obesity. Free Glutamic Acid activates AMPK, because it's an excitotoxin. Further reading on AMPK.
The Short Conclusion:
The Natural Occurrences:
- Eat more food - Gain more body fat - Leptin increases - AMPK decreases (energy storage) - resulting in energy expenditure/use (activity).
- Eat less food - Loose body fat - Leptin decreases (Neuropeptide Y increases [appetite stimulant]) - AMPK increases (energy storage) - resulting in energy consumption (tiredness).
- Eat less food more often - Leptin and NPY kept balanced - AMPK remains balanced - resulting in overall body activity balance.
Free Glutamic Acid (active component in MSG) causes Leptin resistance, activates nutrition stores through AMPK and thus causes Obesity by compromising the body's natural nutrition storage mechanism.
MSG/Free Glutamate stimulates the pancreas to release insulin even when no blood sugar is present. This leads to insulin resistance, aka Type 2 Diabetes.
A popular (and completely natural) appetite stimulant is Cannabis [Cannaboids], aka Marijuana .