Weight gain during menopause is not caused by women eating more. It is caused by a metabolic shift with specific biological origins, and the standard advice to eat less and move more is not always the answer.
On average, women gain two to five kilograms during the transition into menopause. Most of this accumulates in the abdomen, regardless of what they eat or how much they exercise.
They are told this is normal. They are told to eat less, exercise more, and accept that their body is changing. This advice fails for most women who follow it. Not because they lack discipline, but because it addresses the wrong problem.
Weight gain in menopause is driven by specific biological mechanisms that cannot be reversed by calorie reduction. Understanding these mechanisms is the only way to address them effectively.
What estrogen does to fat distribution
Estrogen directly influences where fat is stored in the female body. When levels are sufficient, it directs fat storage preferentially to peripheral areas such as the hips and thighs.
When estrogen levels drop during perimenopause and fall sharply at menopause, this distribution changes. Instead, the body begins to store visceral fat—fat around the internal organs in the abdominal cavity.
Visceral fat differs from fat elsewhere, and not just in appearance. It is metabolically active tissue: it produces pro-inflammatory messengers, disrupts hormonal signaling pathways, and independently worsens insulin resistance.
This creates a cycle that a change in diet alone cannot break, as it addresses the intake rather than the mechanism driving the storage.
The insulin resistance no one explains
The most important metabolic change behind menopausal weight gain is insulin resistance. And it is almost never clearly explained to the women affected.
Insulin is the hormone that signals cells to take up glucose from the blood and convert it into energy. If cells become insensitive to this signal, glucose is no longer used efficiently but is diverted into fat storage, especially visceral fat.
This is primarily not a consequence of too much sugar. It is the consequence of cells no longer producing energy efficiently. And this problem has its root in the decline of NAD⁺.
NAD⁺ is required for the signaling pathways through which insulin controls glucose uptake in muscle cells. If NAD⁺ levels drop in the 30s and 40s, these signaling pathways respond less effectively. This results in insulin resistance, which is intensified by the hormonal changes of perimenopause.
The result is a body that stores fat more easily, burns energy less efficiently, and responds ever more weakly to dietary changes because the underlying metabolic mechanism remains untouched.
NMN supplementation significantly increased muscle insulin sensitivity in postmenopausal women with prediabetes. This opens up potential approaches for age-related metabolic disorders that disproportionately affect women after menopause.
— Yoshino et al., 2021
What research has found on restoring NAD⁺
In 2021, researchers at the Washington University School of Medicine published a randomized, placebo-controlled, and double-blind study in the journal Science. They investigated postmenopausal women with prediabetes—the group in which both NAD⁺ decline and insulin resistance are most advanced and most easily measurable.
After ten weeks of daily NMN intake, the participants showed significantly better muscle insulin sensitivity. In addition, the activity of genes involved in the structure and remodeling of muscle tissue increased.
This is the first human study to show that the restoration of NAD⁺ via NMN leads to measurable improvements in the exact metabolic disorder that drives weight gain during and after menopause.
Another study from 2021, published in the Journal of the International Society of Sports Nutrition, found significantly improved oxygen utilization and endurance performance in amateur runners through NMN. Behind this is the same improvement in mitochondrial efficiency that also determines how well the body burns energy at rest.
Mitochondrial function and metabolic rate are directly linked, and both decline with NAD⁺ levels. That is why research on athletic groups is also relevant to the metabolic health of women who are not athletes.
Which measures really work and why
The measures with the best evidence for menopausal weight have one thing in common: they improve metabolic efficiency and insulin sensitivity rather than just reducing calorie intake.
Strength training is best supported by evidence. It builds and maintains muscle mass. Muscle is the most important site of insulin-mediated glucose uptake and at the same time the tissue most directly affected by NAD⁺ decline and menopausal muscle loss.
Sufficient protein, about 1.6 to 2 grams per kilogram of body weight daily, supports muscle maintenance and produces a lower insulin response than a carbohydrate-heavy diet.
Regular endurance exercise improves mitochondrial function and insulin sensitivity over time.
These measures work because they target the metabolic mechanism rather than just the calorie balance.
Restoring NAD⁺ with NMN works in tandem with these because it improves the cellular conditions under which they exert their effects in the first place. Better mitochondrial function means that strength training triggers a stronger metabolic adaptation. Better insulin sensitivity means that the same dietary choices lead to less fat storage.
Research does not suggest using NMN instead of these fundamentals. It suggests using it as a supplement to restore the cellular environment in which these fundamentals work as they should.
What is realistic to expect
Weight loss is slower during menopause than in younger years. And returning to pre-menopausal weight is often a less realistic and less useful goal than achieving better metabolic health, better body composition, and greater physical capability.
The crucial metric is not the scale. It is the development of visceral fat, insulin sensitivity, and physical resilience over the course of months.
Women who combine strength training, sufficient protein, good sleep, and the restoration of NAD⁺ consistently report that the resistance wanes over time and the body responds to effort like it used to.
This is not a dramatic transformation. It is a metabolic environment shifting back to a functioning state. And that is exactly what the biology of NAD⁺ restoration in postmenopausal women leads us to expect.
Weight gain in menopause has concrete biological causes. And for these causes, there are concrete measures. Women who address the root causes directly achieve results that remain elusive with general dietary advice. The difference does not lie in discipline. It lies in understanding the problem before trying to solve it.
Sources
- Yoshino, M., Yoshino, J., Kayser, B. D., et al. (2021). Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science, 372(6547), 1224–1229. https://doi.org/10.1126/science.abe9985
- Liao, B., Zhao, Y., Wang, D., et al. (2021). NMN supplementation enhances aerobic capacity in amateur runners. JISSN, 18(1), 54. https://doi.org/10.1186/s12970-021-00442-4
- Covarrubias, A. J., Perrone, R., Grozio, A., & Verdin, E. (2021). NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology, 22(2), 119–141. https://doi.org/10.1038/s41580-020-00313-x
- Massudi, H., Grant, R., Braidy, N., et al. (2012). Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLOS ONE, 7(7), e42357. https://doi.org/10.1371/journal.pone.0042357
- Imai, S. I., & Guarente, L. (2014). NAD+ and sirtuins in aging and disease. Trends in Cell Biology, 24(8), 464–471. https://doi.org/10.1016/j.tcb.2014.04.002
- Kim, M., Seol, J., Sato, T., et al. (2022). Effect of 12-week intake of NMN on sleep quality, fatigue, and physical performance. Nutrients, 14(4), 755. https://doi.org/10.3390/nu14040755