Why Extreme Low-Carb Dieting Can Backfire in Perimenopause

Oct 14

Coach Erin McDonald discussing low-carb dieting in perimenopause, balanced nutrition, muscle-building, and sustainable body composition.

For years, many women have been taught that losing body fat means eating less, cutting carbohydrates, skipping meals, or finding an even stricter diet when progress slows.

Coach Erin McDonald says that approach can become increasingly difficult to sustain as women move through perimenopause and beyond.

On Energy Shift with Erin, Erin, a Certified Master Health Coach, Nutrition Coach, and NASM Personal Trainer with 8 Wellness Collective, explains why aggressive calorie restriction, very low-carb diets, keto, carnivore diets, and prolonged fasting may not produce the results women expect in midlife.

Instead of simply restricting more, Erin encourages women to look at whether they are eating enough to support energy, muscle, recovery, and a sustainable body-composition plan.

Why Low-Carb Dieting in Perimenopause May Feel Different

A diet that seemed manageable in your 20s or early 30s may feel very different later.

According to Erin, women can become more sensitive to stress as their hormones begin shifting through perimenopause. That means aggressive dieting may be accompanied by stronger cravings, fatigue, bloating, water retention, and difficulty sustaining the plan.

Her point is not that carbohydrates should come from unlimited processed foods. She encourages women to prioritize whole-food carbohydrate sources such as fruits, vegetables, legumes, beans, and other fiber-rich foods.

Erin describes carbohydrates as an important source of energy and argues that consistently removing too much food from the diet can make it harder to fuel exercise, daily movement, recovery, and the habits that support long-term body-composition goals.

Consistent Fueling Matters More Than Extreme Calorie Cuts

One of the biggest patterns Erin sees is inconsistency.

A woman might eat around 1,200 calories one day, significantly more the next, then cut back again afterward. Erin believes those large swings can make the process more stressful and harder to sustain.

Her preference is to choose an appropriate calorie target and stay relatively close to it from day to day.

That does not mean everyone needs the same number of calories. Erin explains that needs depend partly on body weight, activity, movement, muscle mass, and the goal itself.

The bigger takeaway is simpler: stop automatically assuming lower is better.

For many women, constantly trying to live on 1,200 or 1,400 calories is not the foundation Erin wants to build on, particularly when strength training, daily movement, protein, and adequate nutrition are still missing.

Eating Less and Less Is Not Always the Answer

When fat loss stalls, the automatic response is often to cut calories again.

Erin cautions against repeatedly responding this way.

She explains that extended periods of very low energy intake can affect how a woman feels and functions, especially when restriction is layered on top of hormonal changes that may already be happening during perimenopause.

The cycle can also become difficult to maintain behaviorally.

A woman may severely restrict food throughout the week, only to experience intense hunger and cravings by the weekend. That can lead to eating far more than intended, followed by another round of restriction on Monday.

Instead of creating consistency, the plan becomes an ongoing restrict-and-rebound cycle.

Erin recommends finding a more sustainable calorie intake that still supports the desired goal without requiring extreme swings between eating very little and overeating.

Protein, Fiber, and Carbohydrates All Have a Place

Erin does not advocate replacing one restrictive rule with another.

Her approach centers on balanced meals that provide enough protein, fiber, carbohydrates, fats, and overall energy.

Fiber-rich foods are particularly important in her nutrition philosophy because they contribute to fullness and digestive health. Protein is another priority, especially for women who want to maintain or build muscle.

And carbohydrates, rather than automatically being treated as something to avoid, can help fuel training and everyday activity.

Erin also cautions against assuming that a product is nutritionally superior simply because it carries a "low-carb" or "high-fiber" label. She would rather see women build meals around nutrient-dense whole foods and include regular foods they actually enjoy than depend on highly processed diet substitutes.

Protecting Muscle Becomes Increasingly Important

One of Erin's biggest concerns with repeated crash dieting is the potential loss of muscle.

She notes that preserving and intentionally building muscle becomes especially valuable as women get older. If someone has spent years cycling through restrictive diets without periods of eating enough to support strength training and muscle development, another round of extreme dieting may not address the underlying problem.

Her preferred foundation includes resistance training, adequate nutrition, daily movement, and periods of eating at maintenance rather than trying to remain in a calorie deficit indefinitely.

That changes the goal from simply making the number on the scale smaller to improving overall body composition.

For women who do want to lose body fat, Erin suggests using a controlled fat-loss phase rather than treating restriction as a permanent lifestyle. She discusses spending roughly eight to twelve weeks in a deficit before returning to maintenance, depending on the individual and her goals.

Maintenance Is Part of the Plan, Not a Failure

Diet culture can make maintenance feel like the period between "successful" diets.

Erin sees it very differently.

Maintenance is where the body receives enough energy to support daily life without intentionally pushing for weight loss or weight gain. It can also provide an opportunity to focus on training, muscle development, sleep, energy, and routines that are sustainable outside of a short-term dieting phase.

Once someone has completed a period of fat loss, Erin recommends returning to maintenance rather than immediately pushing into another aggressive deficit.

From there, a woman can decide whether she wants another fat-loss phase, would rather focus on building muscle, or simply wants to maintain the body composition she has achieved.

That approach can be slower than constantly chasing the newest diet, but Erin believes it is much easier to sustain.

The Goal Is to Learn What Your Body Actually Needs

One of the most useful shifts Erin encourages is moving away from generic diet rules.

Instead of automatically blaming age, hormones, metabolism, or carbohydrates when something is not working, she encourages women to understand their own energy needs, nutrition, movement, training, and lifestyle.

That may mean learning how many calories support maintenance, how much protein and fiber fit your needs, how carbohydrates affect your training and energy, and what kind of calorie deficit you can realistically maintain without feeling like you are constantly fighting your body.

Erin's bigger message is simple: your next step does not automatically need to be more restriction.

A balanced plan that includes adequate food, muscle-building, whole-food carbohydrates, protein, fiber, daily movement, and periods at maintenance may be a much more practical way to pursue body-composition goals without repeatedly losing and regaining the same weight.

🎧 Watch Energy Shift With Erin Conversation 🎧

In the complete conversation, Coach Erin McDonald goes deeper into low-carb diets, fasting, calorie restriction, muscle loss, cravings, thyroid and reproductive hormone considerations, and how she approaches fat-loss and maintenance phases with women in midlife.

She also shares practical examples of what balanced nutrition can look like when the goal is to improve body composition without living in a constant cycle of restriction.