With the broad strokes covered, let’s explore the details and the ‘why’ behind some of these components, beginning with energy deficit and balance. But before diving in, it’s important for me to stress that this approach relies heavily on knowing your energy balance requirements. Please take the time to track your total caloric intake and eating habits so that you can accurately calculate your individual needs.

As established in the initial overview, my fat loss strategy relies on the combination of a slight intake restriction AND a little extra cardiovascular exercise to create our total daily energy deficit. Fat loss without exercise is totally possible, but that’s not what we’re doing here. By utilizing these two methods instead of just relying on one, the intensity/demand of each component can be reduced. If our diet is less restrictive and our exercise program is more reasonable, the program will be easier to adhere to and more effective long term. You don’t have to starve yourself to lose weight if exercise is included in your weight loss strategy.

For example, a 10% reduction from a 2000 calorie EB baseline is just 200 calories. We can hit this target by simply removing 9g (9 calories/g) of fat and 30g (4 calories/g) of carbohydrates a day, or with a variety of other carbohydrate/fat combinations. When this minor intake reduction is paired with just a little more fat loss cardiovascular exercise, the total daily energy deficit can easily double. As little as 10 extra minutes a day on top of your current resistance training and cardio routine could be enough to move the scale. I’ve plugged it a few times already, but if you’re not following a detailed fat loss cardio plan, please go check out the Fat Loss Programming guide and the Supplemental Fat Loss sections featured in all of my programs – they’ve got everything you need to complete the exercise half of this formula.

Achieving a minor daily deficit is not incredibly difficult if you approach it the right way – use diet AND exercise together to make it easy.

With the deficit component addressed, let’s discuss refeed days. Why do we need them and why can’t we just maintain a deficit all the time for faster fat loss?

Losing weight is stressful, both emotionally and physiologically. Eating less and exercising more essentially puts our bodies into a starvation mode where they consume themselves for energy… brutal. This catabolic environment caused by caloric restriction and longer duration cardio sessions is essential for efficient fat loss, but unlike the anabolic conditions produced by an energy balance or surplus, we can’t stay in the red indefinitely. When we operate at a long term deficit or attempt to crash diet our way to a leaner physique, we encounter some pretty unfavorable changes to our sex hormones, thyroid function, and cortisol levels. While side effects like decreased testosterone, male hypogonadism, female athlete triad, increased muscle/protein breakdown, decreased MPS, decreased glycogen synthesis/storage, and lower insulin concentrations caused by an impaired endocrine system and dramatically elevated cortisol levels are all far from insignificant issues, the main concern I want to highlight relates to thyroid function and energy expenditure.

If sustained for too long, a constant caloric deficit can significantly slow down our metabolism, resulting in a noticeable drop in total daily energy expenditure. This ‘metabolic downshift’ is called adaptive thermogenesis and it’s a calorie sparing response that our bodies initiate in times of starvation. To keep losing weight in a state of adaptive thermogenesis, we’re forced to gradually eat less and exercise more, which can cause us to develop quite a few unhealthy and unsustainable habits. If this wasn’t already bad enough, our general exercise performance can also be negatively affected due to the limited availability of energy (glycogen delivery and synthesis), possibly leading to emotional distress and a loss in muscle mass due to a steady decline in workout quality.

But wait, there’s more! Things can actually get quite a bit worse when we finally reach our target weight/body composition and go back to ‘normal’ eating habits.

When we lose fat, our fat cells (adipocytes) shrink. In contrast, when we eat too much and gain weight, these same cells expand to hold more stored triglycerides. Our bodies contain roughly the same number of adipocytes during ‘normal’ fluctuations in weight, but these cells change in size in response to varying diet and exercise habits – less fat means smaller fat cells, but we keep the same number. However, this quantity can change.

Adipocytes can become more sensitive to glucose after periods of rapid weight loss. In this hyper-sensitive state, small fat cells (recently shrunk by crash dieting) absorb glucose faster than what can be stored. Instead of expanding in size to hold the newly synthesized triglyceride content, some adipocytes may split to form entirely new cells in a process called hyperplasia – a greater number of fat cells means more total fat storage. When this increased capacity is combined with a drastically slowed metabolism due to adaptive thermogenesis and all of the other unfavorable hormonal changes listed earlier, rapid weight gain that exceeds our initial starting point is entirely possible. Even if we were to eat at our previously established energy balance intake, we could end up way heavier than where we started.

To state the obvious, bad weight loss diets are bad.

While it’s important to understand what CAN go wrong if we don’t approach fat loss in a sensible and safe manner, there’s no need to stress out about anything that’s been mentioned here so far. We can successfully avoid these deficit related issues simply by implementing carbohydrate refeed days. Systematically adding in energy balance and/or minor surplus days through an increased carbohydrate intake allows us to replenish glycogen stores, acutely spike insulin levels, and reset many of the hormonal imbalances that begin to occur after longer deficit periods. If possible, try to pair refeeds with days that don’t contain any cardiovascular exercise.

Regarding carbohydrate food sources, you may find that higher glycemic index complex carbs that spike insulin and blood sugar acutely to be more effective for fat loss than lower GI options that stimulate insulin production for much longer after ingestion. Insulin suppresses fat oxidation and it’s possible that lower GI foods might slow down your progress. However, you might also find the opposite to be true. It’s important that you experiment with different foods to find what makes you feel and perform the best.

Because 1-2 carbohydrate refeed days a week slow down overall fat loss progress, our ability to crash diet down to a smaller size is nearly eliminated. Refeed days force us to embrace sustainable lifestyle changes and develop healthy fat loss habits instead of relying on quick, dirty, and unsafe alternatives.

A 0.5-1% loss in body weight per week is our ‘sustainable lifestyle change’ target range, but you’ll probably find yourself outside of these values at different points throughout your fat loss journey. For most people, losses will be greater at the beginning and will slowly decrease over time due to a mixture of physiological, behavioral, and emotional factors, and that’s totally fine. I recommend that you embrace this common progress decline, set your expectations accordingly, and intentionally taper your losses as the last few pounds drop and you close in on your goal. Slowly phasing out of a fat loss mindset and into a more normal routine can help solidify any recently formed healthy habits and it allows us to work with, not against, a natural change in energy expenditure.

Whether or not you’re OK with this idea of an extended and tapered timeline, it’s important to understand why a natural slowdown occurs at all. Why isn’t weight loss progress linear?

Fading program enthusiasm can partially be to blame for diminished fat loss returns, but the main culprit is a normal and totally expected drop in TDEE due to changes in body mass. Whether you successfully lose 5 or 50 pounds, a leaner version of you will expend fewer calories per day than heavier you once did. Weighing less means you won’t require as much energy to move around, sustain basic bodily functions, or fuel exercise. This drop in TDEE also means that our intake for energy balance will decrease. Many weight loss diets stall here because changes in EB are not considered – intake stays the same despite lower EB requirements. But if we’re consistently tracking our intake, monitoring changes in weight, and regularly assessing energy levels/mood, we should be able to modify daily macronutrient/caloric totals to accommodate for any reductions in TDEE.

Fat and carbohydrate intake quantities can fluctuate within the ranges listed earlier in this guide to help you achieve your desired deficit, but protein needs to stay high due to its effect on muscle retention and appetite control. Protein is arguably the most important macronutrient for fat loss.

Both muscle protein synthesis and lean tissue breakdown can be negatively affected by even the best fat loss diets. The catabolic environment induced by energy restriction has been shown to decrease peak MPS rates by over 25% and significantly increase MPB – a lot less muscle growth and way more loss. These issues are minimized with carbohydrate refeed days, but they’re not completely eliminated. A drop in lean tissue affects our aesthetics but it also hurts performance, as less metabolically active tissue slows fat loss progress, hinders exercise performance, and can lead to injury if MPB is severe enough. We probably won’t experience much muscle growth during extended periods of fat loss, but we can work to maintain everything we’ve built by eating more protein. The per meal intake quantities I suggested in the Maximizing Muscle Mass section are just about what I would aim for here – roughly 40-60g of protein – enough to maximally stimulate MPS and help suppress breakdown.

It’s incredibly important for us to maintain muscle mass by eating more protein while in a caloric deficit, but this macronutrient contributes much more to fat loss success than just tissue preservation. Protein can help us defeat the hunger beast.