MTI’s Nutrition Guidelines: Simple, Proven, Unchanged in 15 Years

By Rob Shaul, Founder

For more than 15 years, MTI’s nutritional guidelines have remained the same. They haven’t changed because they haven’t needed to. They’re simple, sustainable, and proven to work for thousands of mountain and tactical athletes. They don’t rely on supplements, powders, or calorie counting. And they reject diet fads in favor of a single, fundamental truth:

Good, “clean” nutrition starts with eliminating sugar and bad carbs. 

This is the foundation everything else is built on. Get it right, and you’ll shed bodyfat. Get it wrong, and no amount of working out will save you.

The Most Important Rule: Eliminate All Processed Sugar

If you only follow one MTI nutrition rule, follow this one: cut all processed sugar from your diet.

It’s the most powerful single change you can make. Added sugar is the number one driver of unnecessary fat and uncontrollable cravings. Processed sugar is in obvious places like candy, pastries, and soda, but it’s also hiding in foods most never question: condiments, bread, milk, yogurt, fruit juice, and salad dressings. 

Sugar is addicting, gives us a dopamine hit when consumed, and pushes us to eat more. This is why food manufacturers lace just about all processed food with added sugar – even lunch meat.

Our own reasearch results back this up. In an MTI mini-study, athletes who eliminated only sugar and fruit from their diets lost as much weight as athletes who followed far stricter protocols — cutting most carbohydrates or combining low-carb eating with intermittent fasting — over a 3.5-week period. 

• No-sugar group: 3.24% average bodyweight reduction
• Low-carb group: 2.5% reduction
• Low-carb + intermittent fasting: 2.11% reduction

All three groups followed the same training plan. Simply removing processed sugar matched — and slightly exceeded — the fat loss of more restrictive approaches.

This matters. It shows that if you do nothing else — no fasting, no calorie counting, no extreme carb restriction — cutting processed sugar alone will deliver most of the results athletes are looking for.

The same study noted that athletes who cut grains and starchy vegetables in addition to sugar saw slightly better performance gains in strength and work capacity tests. But the difference wasn’t statistically significant given the small sample size. What was clear is that cutting processed sugar alone gets you most of the way there — and it’s the essential starting point for any nutrition plan built for performance. 

Another finding from this study was that itnermittent fasting didn’t accelerate weight loss. 

The nutrition industry loves complexity, and intermittent fasting has been one of the most hyped strategies of the last decade. The athletes in this study who followed a  18-hour daily fasting protocol lost no more weight than those who simply followed MTI’s standard nutrition guidelines without fasting. The low carb + fasting group lost 2.11% bodyweight; the low-carb group lost 2.5% (no fasting) . Performance improvements were similar, and in some assessments, the non-fasting group improved more.

The takeaway: ntermittent fasting does not accelerate fat loss if the quality of your diet is already high. And it introduces a major problem — hunger. Any nutrition plan that leaves you constantly hungry is unsustainable. Hunger breaks discipline, and discipline is what drives long-term results. That’s why MTI’s approach rejects fasting and calorie restriction in favor of satiety through avoiding processed sugar, prioritizing protein and eating whole foods.

The Second Rule: Eliminate Bad Carbs

Once processed sugar is gone, the next major lever is to remove what we call “bad carbs” — grains, starches, and highly processed carbohydrate foods. Bread, pasta, tortillas, potatoes, chips, granola, and beer.  All spike insulin, encourage fat storage, and create dopamine volatility that sugar does.  

Food manufactures have designed foods that are nearly impossible to portion control – and most of these center around bad carbs. Ever try to eat just one potatoe chip? How’d that go? Or just eat a spoonful of ice cream? Nearly impossible. 

In our experience, athletes who cut both processed sugar and bad carbs not only lose fat faster but also perform better. Their energy levels stabilize, recovery improves, and endurance and relative strength scores trend upward.

Cutting processed sugar is step one. Cutting bad carbs is step two. Together, they create the nutritional foundation to achieve an ideal, lean bodyweight based on your height. 

Simplicity and Sustainability

MTI’s nutritional gudiance is deliberately simple. Complexity kills compliance, and compliance — not perfection — is what determines success. Our guidelines don’t change because they don’t need to. They work without tracking calories or macronutrients. They work without hunger. They work without supplements. And they work across the entire spectrum of athlete types and missions.

Here’s what they look like in practice:

Eat only:

• Whole, unprocessed foods.
• Protein as the base of every meal and snack: poultry, fish, beef, pork, eggs.
• Vegetables that grow above the ground: leafy greens, mushrooms, cauliflower, broccoli, green beans, tomatoes, cucumbers, avocados.

Eat in moderation … nuts (not peanuts), nut and seed butters, unflavored Greek yogurt, cottage cheese, berries, and dark chocolate (≥85% cocoa).

Drink only:

• Water, coffee, sparkling water, or diet drinks.
• If drinking alcohol: hard liquor or low-carb hard seltzer. No beer or wine.

Do not eat:

• Any processed sugar or corn syrup.
• All grains: wheat, corn, oats, rice, bread, rolls, tortillas, pasta.
• Beans, including peanuts and peanut butter.
• Vegetables that grow below the ground: potatoes, sweet potatoes, beets.
• Tropical fruits – grapes, bananas, pineapples, mango, and apples. Even natural sugar is sugar. Fruit contains a lot of sugar and because of that is difficult to portion control.n Ever try to eat just one grape?
• Limit other fruit to berries or technically classified fruits like tomatoes, cucumbers, and avocados. 

Do not drink calories …. Avoid milk. (Heavy cream in coffee is okay). Avoid all sugary drinks including sugary coffee drinks, regular soda, and fruit juice. 

At every meal, eat more protein than energy (combined carbs and fats). Make snacks protein-based (keep cooked chicken in the fridge for snacking.) Eat until satisfied — hunger is not part of the plan and if you eat a lot of protein, you won’t be hungry between meals.

Sugar-Subsitutes are okay. Diet soda, splend in coffee, etc. are okay. Sugar substitutes aren’t good for you, but they are better than processes sugar. If you get a sugar craving – drink a Diet Coke, or have some coffee with heavy cream and Splenda – that’s what I do.

Supplements?  Are expensive and you don’t need them. If you must, low carb whey protein shakes are okay – and are sugar-free and sweet – so can help with sugar cravings. Creatine is okay as well – but again neighter is needed if you’re eating enough progrein. 

Alcohol? Try to limit to one day/week, and when you drink avoid beer and wine. Drink hard spirits or hard seltzers for less carbs. Avoid sugar in mixed drinks … so no sugary Magaritas or similar. Try to avoid mixed drinks with fruit juice because of the sugar.

Guidelines by Age

Athletes Under 40:

Follow the nutrition guidelines six days per week. On the seventh day, eat whatever you want. The cheat day isn’t just psychological — it can will reinforce long-term adherence.

Athletes Over 40:

Follow the guidelines seven days per week. No cheat days. Aging slows your metabolism and what you couldn’t have eaten in your 20’s and 30’s and gotten away with, eat after 40 and you’ll add bodyfat. 

Ideal Bodyweights

Nutrition’s impact is on excess body fat – and this is central to ideal bodyweight — a key determinant of strength, endurance, and mission performance. 

Excess weight — especially fat — drags performance down. Mountain and Tactical Athletes primarliy move themselves through space. Even an extra 5 pounds will be noticeable for a Rock Climber, Ice Climber or Ultra Runner competing a climb or race. An extra 10 pounds of weight will negatively impact a Tactical Athlete’s PFT run, ruck push up and pull up score. Fifteen+ pounds overweight and performance can be signifcantly effected. 

Carrying excess bodyfat around isn’t good on your joints, either. Tactical and mountain athletes are already carrying excess load. Cutting 10+ pounds of excess bodyfat will help the longevity of the cartilage  in your ankles, knees, hips and low back. 

Being too light, on the other hand, can compromise strength and hurt mission performance.  MTI’s Relative Strength Assessment is the best tool to find where you stand on strength and how to adjust.

MTI has developed Ideal Bodyweights for mountain athletes, mountain professionals, and tactical athletes. Each athlete type has different fitness demands and, therefore, different optimal bodyweights .

• Mountain athletes prioritize endurance and movement efficiency. They can be lighter.
• Tactical athletes require more relative strength to carry heavy external loads – this extra strengh = extra muscle and can be heavier than mountain athletes and mountain professionals. 
• Mountain professionals fall in between, balancing load carriage and endurance.

For each inch of height, ideal bodyweight increases by about five pounds. Tactical athletes tend to be five pounds heavier than mountain professionals, who are roughly ten pounds heavier than mountain athletes of the same height. 

See MTI’s ideal bodyweight by height charts below:

Why We Haven’t Changed in 15 Years

MTI’s nutritional guidelines haven’t changed in over a decade and a half because they are rooted in physiology, not fashion. They reject shortcuts and trends. They work without supplements. They rely on food, discipline, and simplicity — and they’ve been proven again and again in the field and the lab.

1. Eliminate all processed sugar. This single step drives the most powerful changes in fat loss, energy, and health.

2. Eliminate bad carbs. Grains, starches, and processed carbohydrate foods sabotage performance and body composition.

3. Eat whole foods and prioritize protein. Limit Fruit.

4. Stay consistent — and tighten discipline as you age.

Follow these principles and you’ll shed bodyfat, reach your ideal bodyweight, and keep the fat off, move better, run/ruck/hike faster and increase the longevity of your knees and low back.