The Clause Itself and Why It Feels So Extreme
The provision you described is precise: a base alimony of about $70,000 per month, reduced by $10,000 for every 10 pounds the wife gains from the date of marriage. Put plainly, a 20-pound increase would drop support from $70,000 to $50,000; a 30-pound increase would drop it to $40,000. The logic is framed as an “incentive,” but the mechanism is a financial penalty tied to body weight. That matters because body weight is not a static metric. It fluctuates with age, pregnancy, medication, stress, illness, and simple human variability. Turning that into a dollar amount converts a private, complex aspect of a person into a ledger entry. Even if both parties sign, the structure communicates that appearance is not just valued—it is priced. That is why the clause feels jarring to most people before they even get to questions of legality.
Enforceability Is Narrower Than It Sounds
Saying “it’s enforceable because it’s a contract” skips over how courts actually treat prenups. In the U.S. and the U.K., judges don’t rubber-stamp every term. They look for voluntariness, full disclosure, and whether terms are unconscionable or against public policy at the time of enforcement. Clauses that micromanage personal behavior—weight, intimacy frequency, or daily habits—are often viewed skeptically. Some courts will ignore those provisions even if the rest of the agreement stands. Others may treat the penalty as a disguised attempt to control the person rather than protect assets. So while the couple can sign anything, enforcement is not guaranteed. The practical outcome is usually that asset division and baseline support survive, while intrusive behavioral penalties are weakened or discarded.
What the Clause Is Actually Buying
Look past the numbers and you see what is being purchased: predictability about attraction. The husband anticipates his wealth will grow and fears her appearance may change. He translates that fear into a financial formula. That is not asset protection in the classic sense; it is an attempt to hedge against a perceived decline in desirability. The problem is that attraction is not a fixed output you can lock in with penalties. It is influenced by health, shared life, emotional connection, and time. Pricing it creates a brittle arrangement. It may secure compliance for a period, but it does not create genuine alignment or intimacy.
Selection Versus Management
Your point about selection is where the analysis gets sharp. A prenup is designed to protect property, businesses, and inheritance lines. When it starts dictating how someone must look or behave, it is compensating for doubt. If a partner values fitness, discipline, and a certain lifestyle, the cleanest place to resolve that is before marriage through observation and shared habits. Do they already train regularly, eat in a way that fits your values, and maintain routines over time? If not, a clause won’t install those habits. It can only punish deviation. That distinction matters because management after the fact rarely produces the kind of partnership people actually want.
“People Change” Versus “Patterns Continue”
It’s true that people change, but most change follows patterns already visible. A person who has kept a steady routine for years is more likely to keep it. A person whose habits fluctuate with stress will likely continue to fluctuate. What is often labeled as a sudden change after marriage is frequently the dropping of effort once the incentive to impress is gone. Contracts don’t fix that. They can create external pressure, but they don’t create internal commitment. Over time, external pressure tends to produce resentment, secrecy, or minimal compliance rather than real alignment.
Power, Dignity, and the Cost of Compliance
There is also a power dimension that cannot be ignored. Tying thousands of dollars per month to a body metric places one partner in a position of ongoing evaluation. That can erode dignity and create a monitoring dynamic—what gets measured gets policed. Even if both parties agreed at the outset, living under that structure can change how each person shows up. The spouse subject to the clause may feel reduced to a condition of payment. The spouse benefiting from the clause may feel entitled to enforce it. That dynamic is difficult to square with a partnership based on mutual respect.
What a Strong Prenup Actually Does
A well-constructed prenup handles concrete issues: how pre-marital assets remain separate, how business interests are valued, how debts are allocated, and what spousal support looks like within reasonable bounds. It can include clear schedules for support or waivers that meet legal standards. It does not need to script daily life. When a prenup stays in its lane, it reduces conflict if things end. When it tries to manage identity and behavior, it tends to create conflict even if things don’t end.
Summary and Conclusion: Choose Alignment, Then Protect It
The headline clause grabs attention, but it is not the main lesson. The main lesson is that you cannot contract your way into alignment. You can protect assets with a contract, but you cannot manufacture shared standards, attraction, or discipline with penalties. If those are non-negotiables, they have to be present before the marriage and visible over time. Otherwise, you end up writing terms that signal doubt rather than trust. The smarter approach is to choose a partner whose habits and values already match yours, then use a prenup to protect what you’ve built together and separately.