This is meant as a set of basic guidelines for fat loss, and is nowhere near a complete discussion of the topic. More advanced, detailed guidelines will be posted in future articles as well as an upcoming book.
While numerous factors affect fat gain and loss, by far the most important is energy balance – calorie intake versus calorie expenditure. If you consume more calories than your body burns over a period of time, you will gain fat. If you want to lose fat, you must consume fewer calories than your body burns. There are three basic ways to accomplish this:
Reducing Calorie Intake – How Low Should You Go?
Many people believe they can effectively lose fat simply by exercising or increasing their activity levels, however this approach is highly overrated. Most activities do not burn enough calories to be worth performing solely for that purpose, and a significant increase in activity levels will increase appetite, resulting in proportionally greater calorie consumption if intake isn’t being measured and restricted. Reducing calorie intake is a far more practical and time efficient means of creating an energy deficit.
Ideally, caloric intake should be reduced enough to cause the maximum possible rate of fat loss without a loss of muscle or other lean tissue. Muscle tissue is highly metabolically active, and responsible for a significant portion of the calories you burn each day. A loss of muscle results in reduced metabolic rate, so everything possible should be done to maintain muscle while fat is lost. This is especially important for competitive bodybuilders, who are judged on their muscle size.
Since there is a limit to the rate at which the body can get energy from fat, if the calorie deficit is too large the body will take energy from other tissues. According to a paper in the Journal of Theoretical Biology (1,2), it is estimated the average, moderately active person’s body can get approximately 31 calories of energy per day per pound of fat. This means the maximum one can reduce their calorie intake below maintenance levels without losing muscle is approximately 31 for every pound of fat on their body.* For example, a 180 pound man with 15% body fat would have 27 pounds of fat, so he could reduce his daily calorie intake to 837 below maintenance without losing lean tissue (27 pounds of fat multiplied by 31 = 837). Assuming a maintenance intake of approximately 2700 this would mean a daily caloric intake around 1863 calories.
It is important to note these numbers are based on moderately active people not involved in a regular exercise program and most likely not consuming adequate amounts of protein. The rate at which the body is able to get energy from fat may increase with training and research shows regular resistance training and adequate protein intake helps maintain lean tissue at low calorie intakes (3,4,5,6). However, to maintain as much muscle as possible a conservative approach is best, so caloric deficit should not significantly exceed 31 per pound of body fat.
As fat is lost the caloric deficit must decrease proportionally to avoid loss of lean tissue. If our 180 pound man from the above example consumes 837 calories below maintenance, he should lose approximately 1.67 pounds of fat the first week (837 calories per day multiplied by 7 days = 5859 calories, divided by approximately 3,500 calories in a pound of fat = 1.674). He would then have only 25.33 pounds of fat, and would have to decrease his caloric deficit to approximately 785 below maintenance to avoid muscle loss (25.33 pounds of fat multiplied by 31 = 785.23).
Since the maximal caloric deficit must decrease as fat is lost, it is necessary to regularly re-assess body fat and maintenance calorie intake levels and adjust daily calorie intake appropriately. However, since body fat percentage, basal metabolic rate, and calories burned due to daily activity and calories consumed can not be measured with perfect accuracy, and metabolic rate will decrease slightly over time as a result of your body adjusting to the reduced calorie intake, there is little point in re-assessing too frequently. Weekly or bi-weekly assessment and adjustment is adequate under most circumstances.
Calorie Deficit Versus Nutrient Intake For Obese Individuals
Severely obese individuals may have enough fat to provide close to or even more energy per day than the amount their body requires. However, regardless of the amount of body fat you have, your daily caloric intake should not be reduced below a level necessary for adequate intake of essential macro and micronutrients. The absolute minimum daily calorie intake I would recommend without medical supervision would be approximately 1,200 for men and 1,000 for women.
For example, if you are a 300 pound man with 45% body fat and a maintenance intake of 4,800 calories per day your body fat could theoretically provide enough energy to make up for a daily caloric deficit of 4,185 however, this would result in an intake of only 615. Assuming an ideal bodyweight of approximately 194 pounds, your minimal daily calorie intake should be nearly double that to provide adequate protein and carbohydrate, and adequate amounts of essential vitamins and minerals.
If you are severely obese you may have other health conditions with their own nutritional considerations and should consult with your doctor before making any significant changes to your diet.
Determining Maintenance Calorie Intake
For most moderately active people, multiplying ideal bodyweight (approximately 15% body fat if male, 20% if female) by 15 will provide a reasonably good estimate of daily maintenance calorie intake. Sedentary or smaller people may need to multiply by as little as 12 to 14, while very active or larger people may need to multiply by as high as 16 to 18. (7) Even better would be to measure and record bodyweight and body fat percentage and daily calorie intake over a period of several weeks and calculate maintenance calorie intake based on any changes in bodyweight (if you’re gaining weight your daily caloric intake is over maintenance level, if you’re losing weight it’s below). Better yet would be to be have your resting metabolic rate tested at a physiology lab or fitness center with the appropriate equipment.
Regardless of your initial estimate it will be necessary to measure and record your daily calorie intake and regularly reassess your body fat levels, and to adjust your intake up or down based on how your body responds.
Measuring Body Composition
While there are a variety of methods for determining body fat percentage, the most practical and cost efficient for most people is skinfold measurements. A three-site skinfold test (chest, abdomen and thigh for men, triceps, suprailium and thigh for women) performed by a skilled technician will provide a reasonably accurate measurement of body composition. (8) Most fitness centers and personal training studios offer skinfold testing or another form of body composition testing for a fee.
You can measure your own body fat with the help of a friend and a skinfold caliper, which can be purchased inexpensively online or at most fitness equipment and health food stores. For information on how to perform and determine body fat percentage from skinfold measurements read the article on skinfold testing on this site.
A simpler although slightly less accurate (9) method of measuring body fat is to use circumference measurements. This may be more practical for obese individuals who can be difficult to perform skinfold measurements on.
Calculating Daily Calorie Intake for Fat Loss
Multiply your body fat in pounds by 31 and subtract the result from your daily maintenance calorie intake to determine your minimum daily calorie intake to maintain muscle while losing fat. I do not recommend going below 1,200 calories per day for men, 1,000 for women without medical supervision.
While the above should provide a reasonably good estimate of the daily calorie intake required for near maximal fat loss while maintaining lean tissue, regardless of what your calculations show, remember that practical results are what count. If you do not lose a measurable amount of fat over a period of several weeks gradually reduce your calories until you do, or if your physical or mental performance declines gradually increase your calories until it improves.
Macronutrient Intakes, Meal Timing and Hydration
Although calorie intake is the most important factor for fat loss, the macronutrients you consume also have an effect. Most importantly, adequate protein intake is necessary to maintain lean tissue while eating below maintenance calorie levels, and there are other benefits to higher protein intake such as increased satiety, and a greater metabolic cost compared to fats and carbohydrates. Protein intake should be at least 1 and preferably closer to 1.5 grams per day per pound of “ideal” bodyweight, and consist of primarily meat, fish, eggs and poultry. Fats should be at least 20 to 30 percent of your daily calorie intake, primarily from animal sources or coconut. Carbohydrates make up the remainder, and should come primarily from non-starchy vegetables and smaller amounts of fruit.
Drink plenty of water over the course of each day. Staying adequately hydrated helps to reduce appetite and enables your kidneys to function optimally. If the kidneys are not functioning well, the liver will take on some of their work, reducing its capacity to metabolize fat for energy.
The majority of weight loss supplements produce little or nothing in the way of worthwhile results, and the rare few that do won’t make any noticeable difference unless the above dietary guidelines are being followed. The only supplements I recommend for most people are a basic multivitamin, fish oil, and protein powder in some situations. Studies have shown fish oil helps reduce fat and improves other health factors in combination with regular exercise (10), and protein powder or high-protein meal replacements can be helpful if you are having difficulty getting adequate protein from food or finding time to prepare nutritious meals.
If you are serious about losing body fat a daily food journal is essential. You must measure and record everything you consume on a daily basis. This is the only way to know you are consuming the appropriate number of calories. Since most people significantly underestimate the amount of calories they consume, guessing simply won’t cut it. Although it may seem like a major inconvenience, it only takes a few seconds to weigh, measure or look up the nutritional value of something and record it.
I recommend purchasing a digital food scale and several sets of measuring cups and spoons. You will be using them often, and the more you have the less frequently you will need to wash dishes. You will also need a calorie and nutrient reference book. I suggest The Calorie King Calorie, Fat & Carbohydrate Counter, as it is a convenient size and reasonably comprehensive. I also recommend The Complete Book of Food Counts.
While a smaller notebook is easier to carry around, it will not have adequate space unless you have very small handwriting. Use the largest notebook you are comfortable carrying. If you regularly carry a PDA or laptop computer, another option is using Excel or a word processing program, or one of the many diet tracking programs available.
Record the date and target calorie and macronutrient intakes at the top of the page for each day in your food journal. Divide the page into separate columns for the type and amount of food, calories per item, total calories and meal time. Do the same for protein, carbohydrate and fat if you are tracking these as well. I recommend at least tracking protein in addition to calories to ensure adequate intake.
Under the column for food record the amount and type of item consumed. Under the columns for calories and macronutrients being tracked, record both the value of the food item consumed and the current daily total. Under the column for time, record the time you finished eating. Keeping running totals makes it easier to keep track of how much you’ve consumed. Recording meal time is important to keep meals evenly spaced throughout the day.
Weight and body composition measurements should be recorded at the bottom of the page for the day they are performed, along with the time. On workout days you should also make a note of your workout performance. Other relevant information such as energy level, mood, hunger, etc. could be recorded as well.
Increasing Calorie Expenditure – Exercise and Metabolic Rate
As I mentioned earlier, exercise or increased activity alone is highly overrated for fat loss. Few activities burn enough calories to be worth performing for that purpose, and unless you are restricting your calorie intake it will most likely increase with activity level as a result of increased appetite. While there may be benefit to adding in certain steady-state activities for the severely obese or for individuals who are already very lean and working towards getting their body fat percentage in the low to mid single digits, for the majority of people it is unnecessary.
The most important benefit exercise can provide to someone trying to lose fat is not the increase in calories burned during workouts, but the maintenance or increase of muscle tissue so that metabolic rate does not decrease. This can only effectively be accomplished with resistance training. Most steady-state activities such as aerobics, running, cycling, swimming, etc. do not burn a significant amount of calories per hour, are ineffective for maintaining muscle mass, and can even cause a loss of muscle if performed too long or too often. Additionally, resistance training can provide all of the cardiovascular benefits traditionally associated with these activities (11), so they are unnecessary for any fitness or health related purpose.
The effects of resistance training on muscular strength and hypertrophy are specific to the muscles worked. Performing an exercise for the muscles of the legs will do little to stimulate growth in or maintain the muscles of the arms, and vice versa. Because of this, exercises should be performed for all muscle groups as frequently as individual recovery ability allows to maintain as much muscle mass as possible. For most people, two or three full-body workouts per week is an effective approach. (12, 13) Those with below average exercise tolerance or recovery ability or advanced trainees working at a much higher than average level of intensity may get better results training less frequently or following a split routine to reduce individual workout volume. As trainees become more advanced and train with higher levels of intensity and greater loads, workout volume and frequency should be reduced.
The following are examples of basic, brief but challenging full-body routines I use with new male and female clients. Each exercise is performed for one set of between 8 and 12 repetitions using the maximum weight that can be handled with good form. Some may get better results with a higher or lower repetition range, so some experimentation is recommended. Repetitions are performed slowly and smoothly, using about a three second lifting motion, and a three second lowering motion, without any bouncing or jerking. When an exercise can be performed for 12 or more repetitions, the weight is increased for that exercise during the next workout. Enough rest is permitted after each exercise to allow for a maximum effort on the next.
Sample Basic A&B Routines
If you do not have access to a gym or fitness center an effective full-body routine can be performed with nothing but an adjustable barbell and body-weight floor exercises.
Sample Basic Barbell and Body-Weight Only Routine
If a chinning bar or parallel bars are available chin ups and dips can be substituted for the barbell row and push ups.
Advanced trainees working at a much higher level of intensity and with heavier loads often require a significant reduction in workout volume to avoid overtraining. The following consolidation routines may be more appropriate for some advanced trainees or for those who have very little time to train:
Sample Abbreviated A&B Routines
Keeping Track, Again
Just as it is important to measure and record your daily food intake to ensure you consume an appropriate amount of calories, it is important to record exercise performance to evaluate progress from workout to workout. If your workout performance begins to decline significantly and there are no other obvious causes such as inadequate sleep or illness, it may be an indication your calorie intake is too low and needs to be increased slightly.
Either on a separate page in your food journal or in a workout journal or chart, record the date of your workout and the exercises in order of performance. Record machine settings or type of bar used where applicable for consistency between workouts. Record the amount of resistance used and the number of repetitions completed in strict form. Sloppy or incomplete repetitions should not be recorded. While even a sloppy repetition may provide some exercise benefit, it should not be counted so the resistance used for that exercise is not increased prematurely. For more information on recording workout performance see the article on workout chart nomenclature on this site.
Hard Work + Consistency + Time = Results
Regardless of your current condition, you can significantly reduce your body fat and dramatically improve on your body’s shape and appearance by following the above guidelines. It will not be easy. It will require discipline at the table, hard work in the gym, and a lot of patience. However, if you persevere and are consistent with your diet and your workouts, the results will be worth it.
* “A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290 ± 25) kJ/kg d. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted.” (2)
1. Determining the Maximum Dietary Deficit for Fat Loss. Lyle McDonald. 2006. http://www.mindandmuscle.net/mindandmuscle/magpage.php?artID=35&pageNum=1
2. Alpert SS. A limit on the energy transfer rate from the human fat store in hypophagia. J Theor Biol. 2005 Mar 7;233(1):1-13.
3. Goldberg AL, Etlinger JD, Goldpsink DF, Jablecki C. Mechanism of work-induced hypertrophy of skeletal muscle. Med Sci Sports. 1975 Fall;7(3):185-198.
4. Stiegler P. Cunliffe A. The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during weight loss. Review Article. Sports Medicine. 2006. 36(3):239-262.
5. Layman DK, Evans E, Baum JI, Seyler J, Erickson DJ, Boileau RA. Dietary protein and exercise have additive effects on body composition during weight loss in adult women. J Nutr. 2005 Aug; 135(8):1903-1910.
6. Alexander JL. The role of resistance exercise in weight loss. Strength and Conditioning Journal. 2002 Feb 24(1):65-69.
7. Clark, Nancy. Nancy Clark’s Sports Nutrition Guidebook, 3rd ed. Champaign, IL. Human Kinetics, 2003.
8. Baun WD, Baun MR, Raven PB. A nomogram for the estimate of percent body fat from generalized equations. Research Quarterly for Exercise and Sport. 1981. 52:380-384
9. Hedge SS, Ahuja SR. Assessment of body fat content in young and middle aged men: skinfold method versus girth method. J Postgrad Med. 1996 Oct-Dec:42(4):97-100.
10. AM Hill, JD Buckley, KJ Murphy, et al. Combined effects of omega-3 supplementation and regular exercise on body composition and cardiovascular risk factors. Asia Pac J Clin Nutr, 2005; 14 Suppl: S57.
11. Maisch B, Baum E, Grimm W. Die Auswirkungen dynamischen Krafttrainings nach dem Nautilus-Prinzip auf kardiozirkulatorische Parameter und Ausdauerleistungsfähigkeit (The effects of resistance training according to the Nautilus principles on cardiocirculatory parameters and endurance). Angenommen vom Fachbereich Humanmedizin der Philipps-Universität Marburg am 11. Dezember 2003
12. Carpinelli RN, Otto RM, Winett RA. A Critical Analysis of the ACSM Position Stand on Resistance Training: Insufficient Evidence to Support Recommended Training Protocols. Journal of Exercise Physiology Online 2004;7(3):1-60
13. Smith D, Bruce-Low, S. Strength Training Methods and The Work of Arthur Jones. Journal of Exercise Physiology Online 2004;7(6): 52-68