Cutting Edge Sports Nutrition and Fat Loss With Lyle McDonald

If you’re a coach and don’t know who Lyle McDonald is yet, you need to. I’ve known Lyle for over two decades, and he has always been one step ahead of the mainstream fitness industry in sports nutrition and fat loss.

With an athletic career that spanning three decades, McDonald has “walked the talk” as a cyclist, gymnast, swimmer, triathlete, powerlifter, and speed skater. His interest in sports led him to pursue a degree in kinesiology from UCLA, followed by a lifelong passion for research in nutrition and sports performance.

McDonald got much of the mainstream fitness community’s attention with the 1998 publication of his book, The Ketogenic Diet: A Complete Guide for the Dieter and the Practitioner. Extensively researched, this 323-page nutrition gem provides an extensive review of the pros and cons of this popular, low-carbohydrate diet.

McDonald can dumb down complex research studies for the general population, and his body of work is remarkable. Among his books are The Stubborn Fat Solution, The Protein Book, The Ultimate Diet 2.0, A Guide to Flexible Dieting, Bromocriptine, The Women’s Book: Vol 1, Birth Control and Athletic Performance, and Applied Nutrition for Mixed Sports. Whew! And when he’s not pounding away at his keyboard in his home in Austin, Texas, McDonald engages in online consultations through his company bodyrecompositon.com.

McDonald says he is always working on something new, so you don’t see second editions of his books—they’re one and done! Rather than revisiting old material, he would rather invest his time pursuing new topics.

In this exclusive interview, McDonald took time from his busy schedule to answer some of the most controversial questions about sports nutrition and fat loss for athletes. Let’s get started. 

Freelap USA: What is your opinion of intermittent fasting for athletes, and how should training be modified if fat loss is the primary goal?

Lyle McDonald: Intermittent fasting has come to represent many different approaches. Many athletes are probably familiar with Time-Restricted Eating, which involves people eating within a time window of perhaps 8-10 hours. For an athlete who only trains in the evenings or does easy training in the morning, calorie restriction can be effective since the daily food can be situated around the important workouts

It took decades for sports nutrition to realize that a short-distance sprinter or a power athlete has different nutritional needs than a long-duration endurance athlete, says @lylemcdonald23. Share on X

Another approach I’ve used is Alternate Day Fasting (ADF). This approach alternates “fasting” days (really low calorie/high protein days) with days eating at maintenance calories. The way I use it is to have athletes put the “fasting” days on their easier or off-days with the higher calorie days on their big training days. For someone training intensely 3-4 days per week, this can give them 3-4 “diet” days but still support their training effectively.

Workouts should not change much when fat loss is the goal, besides possibly needing to reduce the total training volume. Recovery is down when you’re eating fewer calories (although ADF helps with that), but athletes must maintain their training intensity to avoid losing muscle or performance. I’d rather see an athlete do fewer repetitions or sets but maintain the intensity of the training.

Freelap USA: Recently, ketogenic diets have become a rage in the fitness industry, with specialized keto products available at supermarkets and health food stores. What type of athletes would benefit most from a keto diet?

Lyle McDonald: While ketogenic diets have mainly been promoted for endurance athletes, they are probably more appropriate for strength/power athletes. Those athletes always “knew” they needed more protein and less carbohydrates than the endurance guys. I mean, how many carbs does a triple in the clean and jerk or a sprinter doing 20m repeats really need?

I prefer moderate carbs for strength/power athletes. It needn’t be the 5-6 g/lb (10-12 g/kg) that a road cyclist might need, but 1.5-2.5 g/lb (3-5 g/kg) is a nice balance of enough to support training without being excessive. The downside of keto diets is that they can cause dehydration and mineral loss.

Freelap USA: Supplement ads promise a competitive edge. What supplements should athletes consider using regularly, and how can they determine which companies are legitimate?

Lyle McDonald: I recommend creatine, fish oils, Vitamin D, and a basic multivitamin (since nobody’s diet is perfect all the time) to basically everyone. For sports with a high anaerobic component, beta-alanine seems to have benefits. I don’t know if people consider caffeine a supplement (more of a daily need), but it absolutely improves strength, power, and endurance.

Workouts should not change much when fat loss is the goal, besides possibly needing to reduce the total training volume, says @lylemcdonald23. Share on X

Protein powders can be useful for athletes who have trouble meeting their protein intakes, especially collegiate athletes, as they may be on the run during the day. I think the biggest change is a proliferation of higher-quality vegetarian proteins such as pea and rice proteins, which can be useful for athletes who don’t want or can’t use a dairy-based protein such as casein or whey. These are typically fortified with amino acids, especially leucine, and can give similar results to what we typically think of as higher-quality proteins. Protein bars also provide a quick and easy form of calories and protein, although they are more of a food than a supplement.

How much protein does an athlete need? I have some articles on my website where I give my protein recommendations. Mine tend to be higher than what you’ll usually see, but I set values for lean body mass rather than total bodyweight, since it’s more accurate. For pure endurance athletes, perhaps 0.8-1 g/lb (~1.75-2.2 g/kg) lean body mass would be appropriate. This number goes up when someone is seeking fat loss, and women can often get by with a little bit less for physiological reasons.

For strength/power athletes, 1.0-1.2 g/lb (2.2-2.5 g/kg) lean body mass would be an appropriate daily intake, and while dieting, this might go as high as 1.4-1.5 g/lb (3.0-3.5 g/kg).

I recommend creatine, fish oils, Vitamin D, and a basic multivitamin (since nobody’s diet is perfect all the time) to basically everyone, says @lylemcdonald23. Share on X

As for supplement brands, I recommend choosing companies that have been around for a long time. NOW is one of my favorite brands. They’ve been around for decades, and I trust their products to be high quality. Solgar is another U.S. company I’d recommend. If you come across a new company selling something at much lower prices than everyone else, I’d suggest staying away.

One concern with athletes is tainted supplements, which can cause athletes to fail a drug test. To learn more, USADA keeps a list of certified and high-risk supplements and companies on their website here.

Freelap USA: How do the nutritional needs of female athletes differ from those of males?

Lyle McDonald: Not as much as you’d think. Some research shows that women need 20 percent less protein than men, but they tend to set it to bodyweight. That’s a body composition thing, since women typically have a higher bodyfat percentage. When you scale things to lean body mass, the differences tend to go away. A woman’s nutritional needs can change slightly during their menstrual cycle, although this may not be as big of an issue for hard-training athletes.

Some research shows that women need 20 percent less protein than men, but they tend to set it to bodyweight…When you scale things to lean body mass, the differences tend to go away, says @lylemcdonald23. Share on X

Women have lower total daily energy expenditures, so they tend to have fewer calories and total food to work within their daily eating. This is mainly due to being smaller overall, so they burn fewer calories at rest and during training. This becomes a real problem when their goal is fat loss since they often can’t fit enough of every nutrient into their daily diet. When protein is set appropriately, that doesn’t leave much room for carbohydrates and fats. The ADF approach I described is a good way around that.

Freelap USA: Is there one general diet optimal for most athletes, such as Paleo? And besides your books, what basic nutrition resources would you recommend?

Lyle McDonald: The modern trend is for athletes to adjust their calorie and carbohydrate intake on a day-to-day basis, depending on their training volume. One hour of endurance training doesn’t have the exact needs as 4-6 hours, and most weight room work burns depressingly few calories.

It took decades for sports nutrition to realize that a short-distance sprinter or a power athlete has different nutritional needs than a long-duration endurance athlete. The former needs fewer calories and doesn’t have the carbohydrate requirements of the latter.

I’ll be honest: I mostly read research at this point. I can’t even recall the last nutrition (general or otherwise) book I read. I recommend that athletes be wary of anybody promising a new magic diet (or supplement) since those fads tend to come and go.

As for supplement brands, I recommend choosing companies that have been around for a long time, says @lylemcdonald23. Share on X

One book I highly recommend for coaches and athletes is Louise Burke’s Practical Sports Nutrition. She’s a top nutrition researcher and has worked with athletes at the Australian Institute of Sport, so she has a background in the science and practice of good sports nutrition. Her book combines the science and practice of sports nutrition with fascinating insights into what we might call the “culture” and “lore” of the different sports—a topic I don’t recall any book I’ve ever read addressing.

To sum up, most of the best athletes eat according to fairly well-established scientific nutritional principles. That means sufficient protein, carbohydrates, and fat, avoiding any of those extremes. They also make sure to fuel their training, recovery, and performance and tend to stay away from magic approaches.

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