Faster Fat Loss:

Intermittent Fasting vs. Starvation

Mode

Things Weight Loss Experts Tell Their Clients…• Calories In = Calories Out

• Burn More Calories Through Exercise To Lose More Weight

• “Everything in Moderation...” and you need to eat “a balanced diet...”

• Eat every 2-3 hours to rev your metabolism…

Simplified View of Insulin Action

• Graphic originally published at http://weightology.net/weightologyweekly/?page_id=319

From Last Time…

• Cortisol• Stress hormone

• Leptin• controls satiety

• Ghrelin• Sparks hunger

• Thyroid• Controls metabolic rate

Hypothetical Carb Cycle

Other Things Nutritionists Say• “You need to eat every 3 hours to keep your

metabolism going”

• “Breakfast is the most important meal of the day”• You need to make it your biggest meal of the

day

• “Your body needs carbs first thing in the morning because your brain needs glucose”

• Do all these things to avoid breaking down your muscle for fuel or going into starvation mode

Does Eating Every 2-3 hours “Rev” my Metabolism?

Meal Frequency: Meta-Analysis

Change in Body Mass Change in Body Fat %

Effects of meal frequency on weight loss and body composition: a meta-analysis. Schoenfeld et al. (2014) Nutrition Reviews, 73(2), 69-82.

Meal Frequency Take Home• No significant impact of

meal frequency on altering daily metabolism

• Possibly an impact if muscle gain is a goal• Evidence that protein

synthesis may max out at doses between 20-40 g/meal

Importance of Meal Frequency• Frequency not that critical an issue

• Total caloric/nutrient intake is most important• What will your clients adhere to?

• Meal frequency is largely a product of personal preference• possibly performance goals

• How many calories do you need?• < 1500 kcal vs. > 3000 kcal• What about the type of macronutrients?

Better Break-”fast”

Big Breakfast

• A number of epidemiological studies have found an association that suggests:• Breakfast eaters have lower BMI• Less body fat• Generally healthier

Nutrient Timing & Severe Caloric Deficit• 94 obese sedentary women

• age 31.67yrs, BMI 33.84 kg/m2

• 8-month study

Diet #1

• Strict low carbohydrate diet • Total calories: 1085 kcal/day

(CHO 17g, PRO 51 g, FAT 78g)

• breakfast 290 kcal (7:12:24g)

• lunch 425 kcal (5:21:28g)• dinner 370 kcal (5:18:26g)

Diet #2

• Low carbohydrate diet, with high calorie breakfast• Total calories: 1240kcal/day

(CHO 97, PRO 93, FAT 46g) • breakfast 610 kcal (58:47:22g)• lunch 395 kcal (34:28:13g)• dinner 235 kcal (5:18:11g)

• Inclusion of a big breakfast significantly:• reduced hunger• increased satiety • decreased desire to eat• increased fullness immediately prior to lunch• reduced carbohydrate craving

D Jakubowicz et al. 2008

4-Month 8-Month

Equal meals -12.62 -4.3

Big breakfast -10.63 -18.15

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Effect of Big Breakfast on Weight Loss

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body

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Tiny Breakfast

• Researchers from Israel put people on a calorically restricted diet for six months:

• Each group consumed the same amount of calories, protein, carbohydrates, and fat but they distributed their carbohydrate intake very differently• control group: ate carbs throughout day• experimental group: consumed the majority of their carbohydrate

intake (approximately 80 percent of the total) at the night.

• Dinner carb group: coffee + 1/5 cup milk and 7 walnut halves• Breakfast carb group: coffee + 1/5 cup milk + 2 slices bread +

cheese

Benefits of Breakfast?• The “carbs for dinner” group actually:

• lost more weight (11.6 kg vs 9.06 kg)• lowered insulin levels to a greater extent (-32% vs +22%)• increased HDL-C more (40.8% vs 26%)• improved TNF-a levels (-9.2% vs +16.2%)• increased adiponectin (43.5% vs 13.9%)

Breakfast by Science

• Recall that epidemiology only describes an association, it does not prove causation• Regular breakfast eaters also tend to:

• Come from a higher socioeconomic status• Exercise regularly• Have fewer bad habits: smoking, eating regular fast food, drinking in excess

• Breakfast certainly benefits some people. But strong evidence that skipping it or minimizing it works better for others

• The key is to look at how your eating pattern affects hunger control• Willpower doesn’t exist... It’s a matter of planning in advance• How you BREAK your FAST (your food choices) may be the key issue...

Intermittent Fasting: Does Science support “Not Eating”?

Calorie Restriction (CR) & Disease

Chronic calorie reduction of at least 30% relative to maintenance calories…

Potential Pathways of CR

Changes in Metabolism

Benefits/Drawbacks

Calorie Restriction (30-40% less than normal)

• Benefits• Fewer signs of chronic disease• Less inflammation• Often, weight loss (particularly males)• Life extension?

• Drawbacks• Difficult to convince people to do it• Females may not respond favourably

• Metabolism downregulates if not careful

Intermittent Fasting in a Nutshell• Alternating periods of eating with not eating (or

eating a lot less than normal)

• Instead of trying to create a deficit of 300-500 kcal/day (normal dieting), you are making deficits of 1500-2000 kcal a couple days a week

Wait a minute

• Isn’t it dangerous to go without food?

• Won’t health suffer if we aren’t eating regular meals?

Fasting: Religious Reasons• Ramadan

• a 4-week period of food and fluid abstinence between the hours of sunrise to sunset

• the length of the fast may vary from 10 to 19 hours each day

Recall History…

Throughout most of human history, we were not regular meal eaters. We followed a more episodic pattern of intake…

But...• But don’t I need to eat regularly, otherwise my body

goes into starvation mode?

Timeline of Tissue Breakdown

36-48 hours before significant amounts of protein start being broken down

Starvation Mode• So I can go longer than 3 hours without my muscles

being broken down for fuel...

Summary

• Our bodies are very well equipped to go without food for 1-2 days at a time• We might not like it, but there is no significant detriment

to our health… we can survive many weeks without food!

Intermittent Fasting: Should You Fast?

Suggested Health Benefits• Reduced

• blood lipids• blood pressure• markers of inflammation• oxidative stress• cancer

• Increased • cell turnover and repair• fat burning• growth hormone release• metabolic rate.

• Improved • appetite control• blood sugar control• cardiovascular function• neuronal plasticity

Fasting Benefits

• Rules are easy to understand (not necessarily follow)• Did you eat something? Yes/No• Less emphasis on weighing/measuring• Not as important to consider low carb vs. low fat

• Dramatic calorie cuts (in a single day, followed by regular eating) may make it tougher for metabolism to down-regulate

• Less food prep and eating time

• Cheaper than other diets• Removing entire meals as opposed to buying less calorie dense foods

Drawbacks

• First 2-3 weeks/fasts are very difficult• Obsess about food

• Intense exercise performance tends to suck

• Females tend to not do well on extended fasts (20+ hours)

• Must monitor binge-eating behaviour

Popular Fasting Protocols

Alternate day fasting (ADF)• Dr. Krista Varady (University of Illinois at Chicago)• 36-hour fast/12-hour feed• you simply eat every other day

• Monday: eat within a 12-hour window (8 AM to 8 PM)• Fast overnight on Monday, and all day/overnight on Tuesday.

• Wednesday: eat again from 8 AM to 8 PM on Wednesday. • Faster overnight on Wednesday and all day Thursday

• Continue...

Eat-Stop-Eat

• Brad Pilon• 24-hour fast, 1 or 2 times per week

• fast for a full 24 hours once or twice per week• Stop eating at 8 PM, fast until 8 PM the next day

• Eat sensibly (higher protein, minimizing processed foods, etc.) the rest of the week

• Flexible, you can choose whichever 24 hours you want• Anecdotally, might be easier to skip breakfast/lunch, eat at dinner

Leangains

• Martin Berkhan• 16-hour fast/8-hour feed

• based on an 8-hour feeding period followed by a 16-hour fast.

• Food rules• diet should be high in protein• should cycle carbohydrates• should include fasted training (just use BCAAs)• should use nutrient timing (eating the bulk of your calories during the post-

exercise period). • On this plan, you fast from, say, 9 PM on Monday night until 1 PM on Tuesday afternoon. If

you’re going to exercise, you’d do so just before 1 PM on Tuesday, with 10 g BCAAs (branched chain amino acids) during training. After training, you eat 2-3 meals before 9 PM, with your biggest meal coming right after exercise. The fast begins again on Tuesday evening until Wednesday at 1 PM, and repeats every day.

Warrior Diet

• Ori Hofmekler

• 20-hour fast/4-hour feed

• either fast, or eat very small amounts of specifically recommended foods, for the first 20 hours of each day, working out during this period of under eating.

• eat the majority of your daily intake within a 4-hour over feeding window.

• Generally, most people place their 4-hour over feeding window at the end of the day, as it’s more convenient for family dinners and after-work training sessions.

Fasting Tricks and Tips

1. Food choices matter. 2. Be patient. It can take 3-6 weeks to get comfortable with it3. Exercise helps4. Timing is everything, you need to figure out your optimal fasting

length5. Progress slowly, don’t jump straight into 24-36 hour fasts6. Don’t overdo it: fasting daily is called an eating disorder7. Eat protein8. It’s still a lifestyle: you can’t do it for a month, then stop9. Some shouldn’t do it: if you have a history of disordered eating,

fasting is a bad idea. Ditto if you have a really fast metabolism.