For simplicity’s sake, weight loss is often boiled down to calories consumed and calories burned. But, as anyone who has tried to lose weight knows, it isn’t always that easy. Hunger gets in the way, you get food envy, and just can’t resist a thick juicy hamburger and side of onion rings, and increasing the number of interval sessions you do every week seems completely unrealistic.
But weight loss could be as simple as activating AMPK, an enzyme in your body that acts like a control panel regulating several metabolic pathways. Increase AMPK activity, like you do during exercise, and your muscle cells will take up glucose, fat cells are oxidized and lipogenesis, the formation of fat, is inhibited. In fact, if you’ve ever heard of the type II diabetes drug metformin, it works, in part, by activating AMPK, leading to decreased glucose production and increased fatty acid oxidation. But, there may be ways to activate AMPK through food as well.
The Power of Polyphenols
Polyphenols are the most prevalent source of antioxidants in our diet. These antioxidant compounds are found in many foods, including tea, coffee, fruit juices, vegetables, cereals, chocolate and dry legumes. And though we consume a good bit of polyphenols, more may be better for weight loss.
Here are the facts:
• The polyphenol resveratrol acts on multiple molecular targets, including AMPK, to decrease both fat cell number and size and improve insulin sensitivity.
• A study in mice found 400 milligrams of resveratrol per kilogram of bodyweight per day, combined with a high-fat diet, didn’t alter the animals’ food intake, but resulted in a decrease in fat tissue. A previous study found that a dose of 22.4 milligrams per kilogram of bodyweight per day, combined with a high-fat diet for a period of a year, did not curb weight gain in mice.
• One study found that resveratrol, combined with two other antioxidants— genistein and quercetin— worked together to synergistically decrease the development of fat cells in murine and human fat. In addition, resveratrol (400 milligrams per kilogram of bodyweight), combined with 2,400 IU vitamin D, 1,040 mg/kg genistein and 2,000 mg/kg quercetin in aged rats increased bone density and led to a decrease in weight gain and fat without a subsequent change in food intake.
• Resveratrol may help decrease some risk factors for disease. In a clinical trial with 10 healthy humans given a high-fat, high-carbohydrate meal on two occasions, supplementation with 100 milligrams of resveratrol, considerably less than the amount used in animal models for weight loss, resulted in an increased expression of several compounds suggestive of a strong decrease in oxidative stress and inflammation
Tip: Supplement with of resveratrol if you want to lose weight. We can’t get the amount of resveratrol used in research studies through diet alone. Though resveratrol isn’t known to be toxic or cause adverse side effects, even in doses of up to five grams a day for a total of 29 days, it’s always a good idea to discuss supplement intake with your physician.
Great Results with Grapefruit
Nootkatone, a constituent of grapefruit, is a natural AMPK activator.
• Animal and cell studies indicate that long-term intake of nootkatone (or 200 milligrams of nootkatone per kilogram of bodyweight as used in some mice studies) significantly decreases high-fat and high-sugar diet induced weight gain, stomach fat accumulation and the development of hyperglycemia and hyperinsulinemia, while increasing total calories burned and stimulating the breakdown of fat in skeletal muscle and the liver.
• Though eating tons of grapefruit may sound like a solution, one grapefruit has about 100 milligrams of nootkatone and it is mainly found in the part we don’t eat— the rind.
Spice Things Up
• Rodent studies show that capsicum, the pungent part of red pepper, increases calories burned and stimulates the breakdown of fat through a series of biochemical reactions.
• Curcumin, a compound extracted from the plant turmeric, activates AMPK and mTOR (a pathway involved in muscle protein synthesis).
• Garlic may not be great for your breath, but it is good for your waistline. Male mice fed a weight gain diet of 45 percent fat diet for eight weeks were given either no supplement or 20 or 50 milligrams of garlic per kilogram of bodyweight over the next seven weeks. Garlic-activated AMPK in several body tissues and both groups given the garlic significantly reduced bodyweight and fat mass.
Tip: Though you’d likely have supplemental doses of these spices for weight loss, go ahead and spice up your food anyway. The more spice, the less fat and sugar you’ll use. Plus, spices have other potential health benefits as well.
In addition to activating AMPK for greater weight-loss results, take a look at your diet and see what you can change. The Paleo diet promises that with the consumption of less processed food and more food that you have to hunt down and pick (though hunting now means the meat aisle and picking means “picking” up from store shelves), you’ll lose weight and feel great. Yet a study published in the American Journal of Clinical Nutrition may have you re-thinking meat, or at least the type of meat you consume, unless you want to pack on the pounds.
In this particular study, scientists followed more than 100,000 men and 270,000 women, ages 25-70, from 10 European countries. They examined their dietary intake, as measured by semi-quantitative food frequency questionnaires and a self-administered quantitative dietary questionnaire, and weight gain over a period of five years.
The researchers’ conclusion? A decrease in meat consumption may improve weight management meat intake could be related to weight gain because of its high-fat and energy content.
But, hold on, chicken and turkey breast, without the skin, are lean and full of protein— the macronutrient that is linked to greater satiety and more calories burned during digestion. And short-term studies have shown that higher protein diets can help obese and overweight people lose more weight compared to higher carbohydrate diets. But, meat and poultry aren’t the only sources of protein around, and studies examining higher protein intakes have incorporated several types of protein including whey, dairy products and nuts. And years of research point toward the fact that calcium-rich milk and dairy foods help preserve lean body mass and slow weight and fat gain, especially if previous calcium intake was low before the addition of dairy foods. In addition, portion-controlled servings of nuts are great for enhancing satiety while having a very minimal effect on blood sugar.
Some things to consider about this study:
• When people with a previous illness as well as those likely to misreport their energy intake at baseline were excluded from the analyses, red meat wasn’t an issue, the link between poultry and weight gain weakened, and processed meat had the strongest association with weight gain. This indicates that some factors associated with meat processing contributed to weight gain— possibly the fat content.
• The authors of this study didn’t take body composition into account. We don’t know if the subjects gained fat mass, lean mass or a combination of both. After all, protein intake plays a vital role in gaining and maintaining lean body mass.
The take-home message? You might want to cut down on processed meats, watch the fat content of the meat you consume, and don’t forget about including other sources of protein in your diet.
To date, many pharmaceutical interventions for obesity have been associated with serious side effects. And while the solution to weight management involves a combination of factors, ramping up AMPK activity while reconsidering your intake of processed meats may help you lose a few extra pounds, painlessly.
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