Study: Exercise Reduces Appetite, But Only Certain Types of Exercise

Dancing!

A new study comfirmed what I’ve experienced about exercise: Cardiovascular exercise (walking, dancing, skating, rowing, etc) reduces appetite, but, strength training does not.

Madeleine Frey, my niece, Figure Skating!

The study…

Abstract

Objective: To investigate the effect of 12 weeks of aerobic (AER) compared with resistance training (RES) on perceived hunger and fullness, together with appetite-related hormones in both the fasted state and postprandially.

Method: Thirty-three inactive, overweight and obese men (age 49±7 years; BMI 30.8±4.2kg/m²) were allocated to either AER exercise (n=12), RES exercise (n=13) or a control group (CON; n=8). AER and RES completed 12 weeks of training (3 sessions per week), while CON continued their sedentary routine. Perceived hunger and fullness, together with appetite-related hormones (active ghrelin, leptin, insulin, pancreatic polypeptide (PP), and peptide tyrosine tyrosine (PYY)) were assessed pre and post-intervention in the fasted state and in response to oral glucose consumption (1284kJ; 75g carbohydrate).

Results: Both AER and RES training elicited a decrease in fat mass (p<0.05), while CON did not. There was no difference in perceived hunger either in the fasted state (p>0.05) or in response to caloric consumption (p>0.05) following the intervention in any group. In contrast, both fasting and postprandial perceived fullness was higher following AER exercise (p<0.05), but not RES exercise or CON. These observations were not associated with alterations in fasting or postprandial active ghrelin, PP or PYY, although fasting and postprandial leptin was reduced following both AER and RES training (p<0.05).

Conclusion: Aerobic exercise training is associated with an increase in satiety, while an equivalent period of resistance training is not.

For more information about exercise’s physiological benefits…

For the full study…

Coping with Halloween Sweets… And Beyond

Click “Play” OR You can watch this video on CNN

Read this article by Katherine in The Huffington Post

The holidays – starting with Halloween – can trip up even the most conscientious dieter. This happened to a client who had lost and kept off 20 pounds successfully. The Halloween trap caught her by surprise. She bought several bags of Snickers, her favorite candy bar, and began a binge that didn’t end until the candy was gone – long before Trick or Treat even began! That brought her up a couple of pounds.

The holidays came and before you know it, she had gained almost ten pounds before winter was out.

With Halloween and the holidays looming, it’s important to determine your strategy for dealing with the temptation of sweets: what you eat, what you bring in your home, and what you serve others. My philosophy is that all foods can be enjoyed in moderation. But there are special challenges posed with some foods, particularly sweets, which have been confirmed by solid science – it’s not just in our heads! Understanding the science behind sweet craving and overeating can help us eat in a more moderate and healthy way.

People have an inborn attraction to sweets. If you don’t believe it, simply watch an infant’s response to something sweet versus, say, a vegetable. There’s an automatic acceptance, even joy, after eating something sweet. On the other hand, vegetables are an acquired taste, which may take 10 – 20 tries before acceptance. This is partly explained by evolution. We’ve been eating naturally sweet foods such as breast milk and fruit for millions of years. They contain life-sustaining nutrients, and a love for those foods helped keep us alive. Also, during evolution, an attraction to scarce calorie-dense foods, such as sweets and fats, improved our chances for survival.

But there are other explanations.  The research surrounding our attraction to sweets has stepped up in recent decades. Scientists are grappling with understanding the calorie imbalances causing the obesity epidemic, which is partly fueled by eating too many sweets.

Our brain chemistry holds an important clue. Research shows that sweets, like many antidepressants, increase the brain chemical, serotonin, which helps regulate mood and appetite. Without carbohydrates, your brain stops regulating serotonin. Eating carbohydrates profoundly improves mood; which is why a handful of candy corn will make you feel better.

When we’re stressed, anxious or depressed, serotonin levels can drop, and one way people modify their moods is by eating carbohydrates. But, Halloween and holiday sweet cravings may be uniquely influenced by seasonal changes, too. Studies show that as days get shorter and we are exposed to less sunshine, serotonin levels drop and this leads to increased carbohydrate cravings in susceptible people.  Women are particularly vulnerable to sweet cravings because their brains have less serotonin than men.

There have been other explanations for women’s reported increased sweet craving and indulging. Some researchers attribute the difference to the female hormone, estrogen. It’s been reported that sweet cravings change according to where a woman is in her menstrual cycle, circumstantial evidence that estrogen may play a role. But the findings are inconsistent, as some report increased cravings during menstruation, while others report higher cravings as a premenstrual symptom, a time when serotonin levels may be low.

But the bottom line is clear: Females overeat sweets compared to males. A study of female rats found they even ate more rat chow when it was sweetened, compared with males, according to a study in the American Journal of Physiology. In animals, having high levels of estrogen is associated with eating more sweets. This theory has yet to be proven in humans.

Cravings and overeating are difficult to study because they can be so subjective and multifactorial. Other researchers stipulate sweet cravings are mainly determined by culture or by psychological and behavioral factors, rather than physiology.

In some cultures, people don’t crave sweets because they haven’t been exposed to them as regularly as Americans. A study of chocolate, for instance, found that American women crave chocolate significantly more than Spanish women. And while a large percentage of American women reported increased chocolate cravings surrounding their menstrual period, Spanish women did not.

Other studies confirm that exposure during childhood is the major determinant of what we crave and are susceptible to overeating.

I copied my mother’s love for sweets and love of baking; it was a fun activity we did together. In college, to combat loneliness, and heck just for fun, I over-indulged my love for sweets (as the pounds went up and up).  I would regularly bake my favorite chocolate chip bars and caramel popcorn, both of which I made in childhood. Study after study shows the importance of parental modeling on a child’s preferences.

Availability and proximity are two of the most important factors science has found influences what we crave and overeat and they probably trump all of the other reasons combined. When tasty foods, such as sweets, are around, we simply eat more of them.

Chances are, a combination of factors is responsible for cravings and overeating sweets at Halloween and the holidays. Holiday sweets are novel, they only comes around once a year. It comes in small pieces so you fool yourself into thinking you’re not eating as much. You put it in bowls around the house and eat it mindlessly.

If you have a strong desire for sweets, it may be a sign that you’re depressed, anxious or stressed. But you don’t have to indulge in sweets to raise your serotonin levels or to feel good. Physical activity, stress management, spending time with loved ones are activities which will also help reduce depression, anxiety and stress. (My client discovered a psychological basis for her binges, which she is successfully averting these days).

Using candy to feel better is not a great solution for your waist line. It is so high calorie, it doesn’t take much to overeat and forget your weight loss plans. For the same calories in a candy bar, you could eat four apples, or maybe you couldn’t – and that’s the point!

Don’t get me wrong, I’m not urging you to be a Halloween Scrooge. I believe it’s possible to have fun with Halloween, and even eat Halloween candy, but still avoid some of the excesses that many of us have fallen victim to in the past. Here are a few suggestions: 

• To reduce the possibility of seasonal cravings, make sure you’re getting 30 minutes to one hour of sunlight each day by taking a walk in the mornings or at lunch. You may be able to “catch up” on the weekend, if you didn’t get enough rays during the week,

• Eat plenty of healthy carbohydrates, such as fruits, vegetables, whole grains and legumes, to keep serotonin at optimum levels and reduce cravings of less healthy carbohydrates, such as refined sugar,
• If you feel driven to eat sweets, it may be a signal that you’re depressed, anxious or stressed. Reduce tension and anxiety by exercising, meditating or talking with loved ones. It’s important to understand the core of the problem and for that, you may need to seek help from a professional,

• If you want to lose weight, keep your candy – or other “extra” calories – to no more than 10% of your daily calories (that’s 200 calories for the average 2,000 calorie intake, or 150 for 1,500 calories). You may even get away with one big splurge on Halloween. But if you splurge for two or more days, it will probably effect your waist line negatively,
• If you can’t resist eating too much candy, wait to buy it on the day of the party or event (or, don’t buy it). This way, the candy won’t be sitting around as a constant temptation,
• Buy only what you need for the event and buy your least favorite candy. Give away the remaining candy at the end of the evening so that there’s nothing left,
• Try fun and healthier alternatives to sweets to have around your home and serve to family and guests, such as popcorn, roasted pumpkin seeds, sliced apples and fruit with nice dips,
• Most importantly, if you do find you overeat, lighten up, don’t dwell on the negative and get over it! Analyze objectively what you can do differently next time,

With awareness and good planning, you can have your sweets and eat them, too!